Hi,

I have been having a few drive letter problems with my computer and flash drives, and I was hoping you wonderful people might be able to help diagnose the issue.

Whenever I connect a flash drive (both my USB stick and my flash mp3 player), it installs properly but does not show the drive letter in my computer.

When I go to my computer->Disk management, the device does show up. If I assign it a drive letter, it goes smoothly, but still does not show up in my computer. I can still access the drive if i open it from the disk management console, but where the drive letter/name usually are it is just blank.

When I restart my computer it still doesnt show in my computer, and when I try to assign the drive letter again, the one that I had previously assigned to my device is not in the drop down list, meaning that it still thinks it is in use.


Computer Specs:

Toshiba Laptop M30
Windows XP service Pack 2




This is a rather annoying problem, and I would really appreciate all the help I can get on this issue.

Thanks and cheers,

bluemouse


Edit: To add, when I try to format it in device manager, i get "The operation did not complete because the drive or partition is not enabled. To enable the partition or volume, restart the comptuer." However, restarting does not work. Disk management says the device is healthy.

Moreover, when I go to Device manager, two of the same drive are present under disk drives. This may be due to the mp3 player having two partitions (one being a small hibernation partition), but i dont know :S It is a Sandisk e260 player, just for that added bit of information.

Just to add a bit more odd information:

When I go into a program such as notepad, or anything where I can see the drive letters when clicking "save as" or something, I can see the drive letter that I Cannot see in My computer. The old drive letter (before disconnect) was still there as well, although nothing is attached to it. I can, however, access all the folders.

I am also experiencing problems with my usb drive disconnecting, which is when I get all these unused but still there drive letters. Every time it disconnects i have to go into disk management and assign a new drive letter again...

Edit2: The problem with my device disconnecting was the power supply to the usb drives. I got an external and it doesnt disconnect, but I am still having problems with that damn drive letter. All the "used" ones clear upon reboot.

Hm, still can't figure it out. I just keep running out of drive letters when I continuously disconnect/reconnect/reassign drive letter with my mp3 player...

How many drives you have in that M30?

C:
D:
E: (should be your USB2 drive)

You can go into adminstrative tools and change the drive letter for D: (DVD/ROM or DVDRW drive to F: this is a quick work around. This problem also comes up on a corp domain, I have to change mapped network drives letters around so that a USB2 drive will should up correcly.

I have a few partitins,etc

C: System Disk
D: CDROM
E: Data Partition
Z: USB2 External drive
??: Flash drives

So you think its because it wants to go to the E:\ driive or something? It "used" to work, but now it does not (maybe before, maybe after I upgraded to xppro sp2, im not quite sure).

What would you suggest given my current setup/mapping?

Cheers

I have a few partitins,etc

C: System Disk
D: CDROM
E: Data Partition
Z: USB2 External drive
??: Flash drives

So you think its because it wants to go to the E:\ driive or something? It "used" to work, but now it does not (maybe before, maybe after I upgraded to xppro sp2, im not quite sure).

What would you suggest given my current setup/mapping?

Cheers

This doesn't make sence. How many partitions do you have off of the C drive?

It might be like this:

C Boot drive
D CDROM
E 1st partition off C
F 2nd Partition off C
G 3rd Partition off C
H USB Hard Drive
I-Z Flash drives

I have two partitions on my CD, my C:/ Drive and my E:/ Drive

I also have an external usb2.0 Hard drive which works fine, and is mapped to the Z:/ Drive.

My CD-ROM is on my D:/ Drive

I then have two flash drives, a USB key and an mp3 player, both of which do not work properly, experiencing the problem I mentioned above.


Extra steps taken:

- Changing the drive letters so that D:/ E:/ F:/ are all free
- Upgraded the BIOS
- Uninstalled the usb drivers and let them reinstall at boot

Both of these flash drives work on other computers, and my USB 2.0 Hard drive works on this computer. I have tried all three usb 2.0 ports.

Hope that clarified it a bit.

Cheers

how many usb ports do you have
3 usb devices and ??ports
usb driver confusion
can try mapping the drives
should keep main hdd to no more n 2 partitions
move or change E to d need to do some juggling round
with this much mass drive CD or DVD should be after the hdd

hope that helps
bluemouse

how many usb ports do you have
3 usb devices and ??ports

I have a mouse and external harddrive plugged in, and then either my mp3 flash or usb key flash plugged in sometimes.

I have 3 ports in my laptop, but one of them is connected to a usb hub with 4 ports. I have tried resolving this issue both with and without anything else plugged in besides one of the flash drives.


usb driver confusion
can try mapping the drives

I have tried mapping the drives. Only mapping the flash drives fail



should keep main hdd to no more n 2 partitions


Main hdd only has 2 partitions, C:/ and E:/



move or change E to d need to do some juggling round

Tried that



with this much mass drive CD or DVD should be after the hdd


CD Drive is now F:/ instead of D:/ but I still have the same problem


hope that helps
bluemouse

Thanks for trying though :) You did better than microsoft or toshiba....


I just love it when level 2 tech support guys on both ends first suggest that it is a fault with the other company (ie if I call toshiba, they say it is a problem with the OS, and if i call microsoft they say it is a toshiba driver issue)

They then proceed to tell me that formatting my hard drive would most likely solve the issue, as if I didnt know that already, and am only calling to avoid having to do that in the first place.....

I even had to convince the level 2 microsoft guy that I was running Service pack 2, even when he was remotely connected to my computer and could see that it said sp2 under my computer...

Somehting else TRULY odd....

Like I said, when I go to my computer, i cannot see the flash drive. However, If i go to disk management and map it, i can still open it from there. When I check the folders tab in the now opened explorer window, i cannot see the drive still under my computer.

HOWEVER, if I create a test html page (test.html), open it in internet explorer, and then get rid of the test.html so the url/path is just file:///D:/ (where D is the drive mapping of the flash drive), I CAN see it in the left (folder) pane. It appears that internet explorer acting as windows explorer can see it fine, its just my computer/windows explorer that has problems. Of course, if I unplug it i still need to remap.

I really am completely stumped on this issue....

Gremlins? In the system...

im beginning to think so...

I haven't thoroughly read this thread, but here's some ideas.

Do you have any network drives mapped? Windows seems to get confused between the two sometimes and I don't think this is just a network drive mapping problem.

For troubleshooting, disconnect your USB drive and try reassigning Z, Y, X, etc.. to your internal drive partitions, optical drives and network drives to free up lower letters (D, E, G etc..). Reconnect your USB drive and reassign a lower drive letter to it such as E instead. What happens?

Since drive letter issues are more common than they should be with Windows, it appears others have created drive letter managers. Check this out (http://www.google.com/search?q=usb+drive+letter+manager&start=0&ie=utf-8&oe=utf-8&client=firefox-a&rls=org.mozilla:en-US:official). Let us know if using a 3rd party tool gives you any positive results.

ack I forgot that one
ya I had a virtual drive use a usb drive letter
usb device vanished
this happened with flash disk drive as well
usb driver port assignment is scarey
i wonder if you can make xp see them as a standard drive (not removeable)
looking at doing testing with my hotswap drives thought I saw something about

I haven't thoroughly read this thread, but here's some ideas.

Do you have any network drives mapped? Windows seems to get confused between the two sometimes and I don't think this is just a network drive mapping problem.

For troubleshooting, disconnect your USB drive and try reassigning Z, Y, X, etc.. to your internal drive partitions, optical drives and network drives to free up lower letters (D, E, G etc..). Reconnect your USB drive and reassign a lower drive letter to it such as E instead. What happens?

Since drive letter issues are more common than they should be with Windows, it appears others have created drive letter managers. Check this out (http://www.google.com/search?q=usb+drive+letter+manager&start=0&ie=utf-8&oe=utf-8&client=firefox-a&rls=org.mozilla:en-US:official). Let us know if using a 3rd party tool gives you any positive results.

I dont have a network drive, and I did try reassigning my D:/ Drive and E:/ drive to something like R and S. Didnt do anything :S Even if that is my problem though, it should show once I remap the drive letters, and it doesnt. THen there is that odd thing about showing in Internet explorer, but not my computer->windows explorer.

Ok I have the exact same problem and I have tried the above and nothing seems to work.

It is very annoying because I have tried both USB sticks with the same outcome

Reinstall your USB drivers: Device manager>USB controllers>Remove all under that tree. Reboot your PC with all your devices that use a letter on the My Computer list and let it reinstall the USB controllers. See if that helps.

Have you tried different ports, or if you're using an external hub, a port directly connected to your motherboard (eg the back ones)?

Nope. No luck, still can’t recognise it still :(

Reinstall your USB drivers: Device manager>USB controllers>Remove all under that tree. Reboot your PC with all your devices that use a letter on the My Computer list and let it reinstall the USB controllers. See if that helps.

Have you tried different ports, or if you're using an external hub, a port directly connected to your motherboard (eg the back ones)?


I have tried all 3 ports, plus a powered hub with no luck. I have also tried removing the controllers and letting it reinstall, but that didnt work either :S

Sphere: How did you install windows? Clean install? upgrade? Lets see if we can work out some similarities and narrow it down. Is yours a laptop?

Windows was installed with this yes, I used to be able to use them but all of a sudden it won’t pick them up now :(. It is a laptop and I have just done a windows xp repair with no luck still. I have tried all 4 USB slots with the sticks and none are recognised. I am using them though so they aren’t damaged.

I mean I can see then when I go to my computer>manage>disk management

This is very annoying because I also can’t do a windows update as well for some reason :(

SAME PROBLEM! I have problems with windows update too, and I have a laptop... repair did jack all.

It seems that it just stopped working after a while. I upgraded from XP home sp1 to pro sp2 though, did you do something similar?

Anyone have any more suggestions?

Cheers

Any chance either of you have attempted to use a 3rd party drive letter manager?

I'd just be curious if it works or not, although it would technically be a workaround and not a solution.

SAME PROBLEM! I have problems with windows update too, and I have a laptop... repair did jack all.

It seems that it just stopped working after a while. I upgraded from XP home sp1 to pro sp2 though, did you do something similar?

Anyone have any more suggestions?

Cheers

No i have had sp2 since i got this laptop. This is soooooooo anoying

Havent tried it, though Ihave tried using the gmail drive thing. Mybe that screwed it up.

SAME PROBLEM! I have problems with windows update too, and I have a laptop... repair did jack all.

It seems that it just stopped working after a while. I upgraded from XP home sp1 to pro sp2 though, did you do something similar?

Anyone have any more suggestions?

Cheers


How did you upgrade from Home to Pro?

Running Home then upgrade to Pro.

Can you just backup that drive
Then blow it out and install a new copy of Pro.
Try it this way, if it doesn't work then have the M30 serviced.
Faulty USB ports on the MOBO...

Replacement of the MOBO....

That cant be my problem because all my other stuff is working through the usb ports

That cant be my problem because all my other stuff is working through the usb portsImproper current can cause all sorts of nearly unexplainable problems, but I agree - this definitely sounds like a software issue. I've just been casually following this post, but when I get some more time I'm going to search for answers. I like a good mystery. :)

Don't forget about trying a 3rd party drive letter manager when you get the chance. I'd like to see the results, if there are any worth seeing.

You know, I was thinking, maybe using diskpart will do something different. You can access diskpart by going to Start > Run > cmd and type diskpart in the cmd shell. It might also help us get some more info about you have been looking at.

So type in the command to fire up diskpart - you'll be taken to the diskpart command shell. DISKPART>. At the shell, type:

list volume
list disk - Copy and paste the results in this thread

Is your USB drive listed anywhere in there? It should show up under the volume list for sure.

Using the volume number, issue the command select volume # - '#' should be your USB drive's volume number.

This should bring your USB volume into focus so any commands you type will apply to that volume only. Now issue the command: assign letter=M - (or whatever letter you'd like)


I'm just curious if this works and if the changes stick or not, so please try it and let us know what happens.

You may also poke around a bit. Just type help for the full list of options or [command] help for sub options. If you find anything useful or unexpected, please post it here so we can take a look.

Havent tried, but i can.

What I dont understand is why it shows up in INTERNET explorer and not windows explorer. Are they not the same shells?

I also get this problem when I go into disk manager where it comes up fine the 1st time, but if i disconnect the flash drive and plug it back in, it doesnt seem to want to go into disk management. I seem to have a similar problem with diskpart as well. It went in when I had already assigned a drive letter once, but when I disconnected and reconnected, it doesnt do anything anymore. Diskpart just closes after about 30 seconds or just stays at the "On computer: XXXX" line, while Disk management sometimes freezes at the "Connecting to logical device manager service" status.

Havent tried, but i can.

What I dont understand is why it shows up in INTERNET explorer and not windows explorer. Are they not the same shells?

There's something supressing that drive letter from showing in Windows Explorer. It's there... and accessible... It just doesn't show up.

It makes sense that if it didn't work WE, it wouldn't work in IE either... But as we see, that's not the case. So your logic is sound, but it could be some specific, obscure bug which affects the way WE enumerates or displays drives just under the "My Computer" window.

We'll just have to keep an open mind with this one, because it seems to defy most intellegent conceptions. :)

hm,

Ending the dmadmin.exe task flixes the freezing problem....



RESULTS:


Microsoft DiskPart version 5.1.3565

Copyright (C) 1999-2003 Microsoft Corporation.
On computer: GRAL

DISKPART> list volume

Volume ### Ltr Label Fs Type Size Status Info
---------- --- ----------- ----- ---------- ------- --------- --------
Volume 0 I DVD-ROM 0 B
Volume 1 C System Driv NTFS Partition 60 GB Healthy System
Volume 2 E Data Drive NTFS Partition 7217 MB Healthy
Volume 3 MY USB FAT Removeable 62 MB

DISKPART> list disk

Disk ### Status Size Free Dyn Gpt
-------- ---------- ------- ------- --- ---
Disk 0 Online 75 GB 0 B

DISKPART> select volume 3

Volume 3 is the selected volume.

DISKPART> list disk

Disk ### Status Size Free Dyn Gpt
-------- ---------- ------- ------- --- ---
Disk 0 Online 75 GB 0 B

DISKPART> assign letter = M

DiskPart successfully assigned the drive letter or mount point.

DISKPART> list volume

Volume ### Ltr Label Fs Type Size Status Info
---------- --- ----------- ----- ---------- ------- --------- --------
Volume 0 I DVD-ROM 0 B
Volume 1 C System Driv NTFS Partition 60 GB Healthy System
Volume 2 E Data Drive NTFS Partition 7217 MB Healthy
* Volume 3 M MY USB FAT Removeable 62 MB




Still doesnt show up in my computer though....


And the other problem is that once I use up a letter and disconnect the device, i can no longer map anything to it until I reboot, almost as if the computer still thinks it is there. If I remap the drive without disconnecting then I can use the old letter fine...

What drivers control this stuff? Also, I found something called USBdetector.exe on my computer and uninstalled it, but it didnt do anything useful. I dont know where it came from really, or where to download it again.

How did you upgrade from Home to Pro?

Running Home then upgrade to Pro.

Can you just backup that drive
Then blow it out and install a new copy of Pro.
Try it this way, if it doesn't work then have the M30 serviced.
Faulty USB ports on the MOBO...

Replacement of the MOBO....

Yes, i was running home and then upgraded, but i think it was faulty before that, just cant remember for sure.

Formatting is not an option, because I dont have enough space and dont really want to spend like 80 bux going to some pc repair shop to do a backup. I also have a lot of custom configs on here which took me a while to do, as well as some software installed where I lost the cd.

My USB ports are not faulty, because my external hdd works fine, and the USB key is recognized when I dual boot ubuntu.

Edit: I just tried driveman as a 3rd party drive manager, and it only detects it once i map the drive

ok tried all of those and no luck, i mean if i could get Microsoft update working i reckon it would fix it but everytime i try i get this error code:

[Error number: 0x8024402F]

re: windows update problem.. This site (http://www.microsoft.com/windowsxp/expertzone/newsgroups/reader.mspx?&query=0x8024402f&lang=en&cr=US&guid=&sloc=en-us&dg=microsoft.public.windowsupdate&p=1&tid=47d16ecf-a0a2-48c5-b7f2-11d0e9da57a4) may help.. here's the summary:

try clearing out your temp files:
Internet Options>
-delete Cookies
-delete files
-[settings]>[view objects]>delete if any there (optional)
Close IE and reopen or reboot your PC and try..

Check your router/internet connection and settings, check your firewall etc.

Curious.. does your USB sticks pick up in WE like normal on other pcs?

What drivers control this stuff? Also, I found something called USBdetector.exe on my computer and uninstalled it, but it didnt do anything useful. I dont know where it came from really, or where to download it again.Windows uses a generic 'usbstor' driver which handles virtually any USB storage device. It's included with your Windows install.

This is different than your USB host controller drivers. If there were a problem with usbstor, reinstalling SP2 (for example) should fix whatever problems may exist with your USB storage driver.

where can I get just usbstor by itself?

If it is an OS issue, then what could be the causes?

The only thing I can think of is drivers, so which drivers could cause the issue?

Just one more thing. I have a SD card reader on my laptop and I have the same problems with them too in that slot. Therefore, it HAS to be some driver that deals with flash memory, since my USB flash key, USB mp3 flash player and CARD flash disk all do the same thing.

Just one more thing. I have a SD card reader on my laptop and I have the same problems with them too in that slot. Therefore, it HAS to be some driver that deals with flash memory, since my USB flash key, USB mp3 flash player and CARD flash disk all do the same thing.

Your SD-card reader is probably connected via your internal USB bus, so that doesn't necessarily mean it isn't USB. But I think your USB storage drivers are much more likely a cause than USB itself. I don't 100% rule anything out, but I don't believe it is either. Purely based on conjecture, I think it some quirky Windows problem with assigning drive letters under a certain set of circumstances. Of course, I am not a software engineer, so my guess is as good as yours.

If you're looking to install your USB mass storage driver, your system's original usbstor.sys (driver), usbstor.pf (service) and usbstor.inf (setup information) will be located on your XP install disc. You'll find the files in the i386 folder somewhere (may be in subfolders.. not sure) and the last letter of the extension is usually chopped at the end like so: usbstor.sys will be usbstor.sy_ on your CD.

Here are the directories where these files belong and should be copied to:

usbstor.sys - C:\Windows\System32\Drivers\
usbstor.pf - C:\Windows\INF\
usbstor.ini - C:\Windows\INF\


The only complication I forsee is Windows File Protection. If you copy those files over, they'll just get overwritten (without any warning) by the originals cached by WFP. We need to disable WFP before copying those files.

Since SP2, MS has removed the option to disable WFP, although we can still enlist the aid of an application (or registry setting) to disable WFP at this point. Search around and you'll find something as I don't have any recommendations.

You can also use SFC (System File Checker) from the command prompt. Just type in SFC /SCANNOW and make sure you have your Windows XP disc in the original install drive. It will scan your computer for corrupted or changed versions of system files, which I'm assuming includes usbstor.sys and .pf and probably ini and replace them with nice, fresh versions from the CD.

There have been updates to the XP USB storage driver over the years as well, prior and probably after SP2. So reinstalling your SP2 would probably have the same affect as copying or SFCing the files.

Just some more ideas... Good luck!

I already tried the sfc, and it screwed up my nvidia drivers :S It also took a while, since it kept prompting my for my cd when I already had it in, and I had to mash "retry" about 100 times to get it to complete. Still have the same problem though :S

Thanks for the ideas though :)

Can anyone give me the installation for the windows usb driver?

Would the sd card slot be connected via internal USB? How would I check that?

Can anyone give me the installation for the windows usb driver?

What version of Windows are you talking about? XP has it's own USB drivers, but if don't trust them, try searching driverguide.com

FIXED IT!

It had something to do with the registry, and nothing to do with the drivers at all.



**** PLEASE ENSURE THAT YOU EXPORT THE FILES BEFORE DELETING SO YOU CAN IMPORT IF YOU SCREW UP ****

Be sure to try remapping your drive letters before attempting this fix. It is only to solve the issue once the drive letters refuse to remap properly

For Windows XP Only - Not sure of the exact registry keys for 2000, but should be similar

**********************************************************************
1) Go into start -> run -> regedit -> hit ok

2) Navigate to:
[HKEY_LOCAL_MACHINE\SYSTEM\MountedDevice1]

3)file -> export (the mounteddevices1 folder) and save to a chosen location

4) delete all the dosdevices drives (ie. \dosdevices\C: )

5) I cant remember if i did it to the "mountd devices" folder too, so dont do it at first but if it doesnt work then do it after

6) go to [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E967-E325-11CE-BFC1-08002BE10318}]

7) Export this too and save to a chosen location that you will remember

8) delete the upperfilter key

9) reboot and try plugging in your device.

This actually didnt work for me when i tried it, but then i tried plugging in my device an hour later and it worked flawlessly (all 3 flash drives)

Hope this helps! Your registry may be slightly different, but look in there, there are probably a bunch of keys that are screwing it up.

Cheers :)

OMG DUDE I LOVE YOU!!!!!!!!!!

Its back working, I appreciate everyone’s help Thank you for taking the time and helping :)

Its back working, I appreciate everyone’s help Thank you for taking the time and helping :)

Ditto :) .

WAHAHAHAHA FIXED IT!

It had something to do with the registry, and nothing to do with the drivers at all.

**** EXPORT THE SELECTED FOLDERS BEFORE DOING THIS ****

1) Go into start -> run -> regedit -> hit ok

2) Navigate to:
[HKEY_LOCAL_MACHINE\SYSTEM\MountedDevice1]

3)file -> export (the mounteddevices1 folder)

4) delete all the dosdevices drives (ie \dosdevices\C:)

5) I cant remember if i did it to the "mountd devices" folder too, so dont do it at first but if it doesnt work then do it after

6) go to [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E967-E325-11CE-BFC1-08002BE10318}]

7) Export this too

8) delete the upperfilter key

9) reboot and try plugging in your device.

This actually didnt work for me when i tried it, but then i tried plugging in my device an hour later and it worked flawlessly (all 3 flash drives)

Hope this helps! Your registry may be slightly different, but look in there, there are probably a bunch of keys that are screwing it up.

Cheers :)


I've got the same problem with my thumb drives not showing up in Windows Explorer so I was really excited when I saw your post. I saved the registry folders that you said to back up but after I destroyed my registry, XP wouldn't boot and I didn't know how to restore them. :) :P So I booted in safe mode and restored a Restore Point. That got the registry restored and XP booting again. I probably should have been more cautious but I deleted all the \??\Volume entries and a lot of the ones below those like (ie \dosdevices\C:). I really hope I can figure out how to tailor your fix to my machine and get the auto-drive assignment working again.

Moral of the story: Don't delete registry entries unless you know EXACTLY what you're doing.

Thanks for this solution. I'm not sure what went awry with my system, but I suspect it had something to do with a new version of McAfee that I installed a couple weeks back. It was called McAfee Plus. I'm using XP Media Edition on my HP Pavilion. It was a replacement to the previous online version of McAfee. After installing it my operating system started going stupid. I ended up having to do a system repair. It seemed to work OK for a couple days then started going stupid again.

I found out that McAfee has crappy support options - some dumb online chat thing that makes you type forever and a support line that is a pay per minute 900 number. I'm not paying to debug any company's software! I uninstalled, ran their cleanup utility and demanded a refund.

I got a call a couple days later to do a survey. Too bad they spend more time doing survey's than they do supporting the customer. They can do all the survey's they want now. I'm not paying to install crap.

As for HP, I spent about 3 hours working on this problem with them (three different support people) and they ended by telling me that I'd have to do a clean install. NO WAY! Another couple hours of research and I stumbled across this one and it worked. Thanks folks.

thanks so much!!! i have been having the same problem for months and your instruction with the registry fixed everything!!! i thought reformatting was the only way to repair it to how it used to be but now its working perfectly!! thanks so much!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Same here! The clear instructions were greatly appreciated.

I don't have a MountedDevice1 folder in my registry just a MountedDevice folder. I tried removing the DOS files from this but it didn't help. Any suggestions would be greatly appreciated.

I solved this problem another way round. Deleting the upperfilter I see more like a workaround. I think the upperfilter is there for a reason. Btw I don't think you have to delete the MountedDevice thing. The Bluemouse (workaround) works fine for me just deleting the upperfilter. Take a copy of the key (or better of the whole registry) before you do anything. Don't mess with the registry if you don't know what you are doing. After you have deleted the upperfilter do a reboot. After the reboot Windows should tell you it has installed some hardware and want's to reboot. Do that and you should be good. Works for me. Now, here's what I did instead of deleting the upperfilter. I found out the file SPTD.SYS in C:\windows\system32\drivers (XP) was the reason for bad behaviour. The SPTD.SYS and SPTDxxx.SYS belongs to Daemon Tools. The xxx are some numbers. So, by uninstalling Daemon Tools and rebooting, same thing happend. After reboot windows installed some hardware and after a new reboot everything was ok. If you have Daemon Tools installed, to figure out if thats the reason, move the two files mentioned above to an empty folder. Do a reboot. After the reboot windows should install some hardware. If you can see your Flash Drive after a new reboot you know the reason. I don't know who's to blame. The Daemon Tools or the Flash Drive. But there have been some problems with SPTD.SYS over time. Another thing. After doing it, no matter what solution you use, take a look at your drive letters. They maybe changed. Remap them back to where they were from the start. Sorry for my bad english.:o

Peace
Cheers

Happened to me after a "less than smoothe" SP2 installation.
Your fix worked instantly.

I keep getting an "insert disk" error on booting but I can live with that.

brainer, that probably has to do more with your boot options than with the hd. maybe you have it set to boot off usb or cd before hard drive. Check your bios settings.