I found a MUCH easier solution to this issue. I simply deleted the device from the Device Manager and rebooted. When I rebooted the drive letter was assigned to D: instead of E:. Here is exactly how I did it:

1) Right-click My Computer and choose Manage
2) Select Device Manger
3) Expand Disk Drives (make sure your SD card is inserted before you go to Device Manager)
4) Left-click on SD Memory Card and choose Uninstall
5) Reboot

Hi guys, new guy here.

Just thought I'd register to let you know another way of fixing this is similar to Redwin's idea, however it doesn't require a restart.

If you have Daemon tools installed, simply right click on the tray icon and set the amount of virtual drives to 'disabled'

worked for me, who knows.

Thank you Bluemouse!! After scouring the internet for 3 weeks this finally worked!! I backed up the registry filed like you said, and after a blue screen and a couple of reboots, I plugged in my mass storage device and WALA!! It was automatically assigned letter F; by the XP explorer!! Letter E: was assigned to a virtual drive on my Lenovo IBM, drive C:, used for backup and recovery. I suspect that there was a conflict before, with the IBM virtual drive and my USB mass storage, both trying to use the E: drive. I had tried using Disk Manager to assign another letter to the USB mass storage, but it still had not worked. Oddly enough I was able to access the USB mass storage device from the the Device Manager and other programs like Outlook for attachments, but NOT through XP Explorer. NOW it works!! Just a question: I noticed that the DOS-Drive letters were recreated in the mounted device folder.... How about the upper-filter thingy? Is that automatically re-installed as well?

Now another issue: How do I get my Plug and Play to work?? I normally wouldn't care, but I'm trying to install a Canon printer that relies on the plug n play for installation. Before I reinstalled Windows XP, I used to get a "New Hardware Detected". Not any more. Anybody??

Just some additional info/suggestions for anyone else finding their way to this thread...

There are several different methods to fix problems caused by "Driver Letter Conflicts" (which is typically the root cause of the problem described in this thread)

IMHO: The simplest (and most thorough) solution is using the DriveCleanup Tool

• The "Drive Letter Conflict" occurs because your USB device is competing for the drive letter with some old / prior installation data still on your computer.
• And your USB device has lost the battle for the drive letter! (so the USB device appears in Device Manager but not My Computer or Explorer with a drive letter)
• Running the DriveCleanup Tool will uninstall / remove old installation data for all currently unplugged USB storage devices
• So the next time you replug the USB storage device, Windows does a new, clean install and reassigns it the next available drive letter

Here's some helpful links for reference
> See this post for How to use the DriveCleanupTool
> If you're still having USB issues see Troubleshoot: Windows Won't Recognize Your USB Hard Drive (<= rewritten 11/21/09. So if you've read this post before is worth taking another look!)
> To help avoid problems in the future see How to Avoid Problems with USB Storage Devices

i have thru the regedit....
where should i export the things u said us to export..
more over i dint mobile device1 in my regedit. could u make it little more clear on that

@pearls
Try this. See How to Cleanup and Remove old USB Mass Storage Drivers

John Mart and BlueMouse,

I want to thank you both for helping me fix my USB access problems that I had done many hours of searching with no joy till now. I'm so thankful that I registered on this forum to thank you both. I'll describe my fix as it might help others, as this thread helped me.

*** MY SYMPTOMS WERE: ***
1. SanDisk 12-in-one USB card reader no show in Explorer. Showed in Disk Management but no drive letter. Trying to add a drive letter got an error msg saying that the drive or volume was not available. Reboot to make available. (paraphrasing since I did not write the exact wording down) --- Bottom line, no way to access the card reader.

2. Thermaltake external USB hard drive no show in Explorer. Showed in Disk Managment with a drive letter. Able to open drive from Disk Management only. Able to do backup or restore using TeraByte Image For Windows. Not accesible using Acronis TrueImage 8 (I guess since not registered in Explorer).

*** THE FIX: ***
Using John Mart's UpperFilter tips, I found that my upperfilter was set as snapman, Phylock, PartMgr. I changed the order to PartMgr, Phylock, snapman per John's post. To change the order, just click on the UpperFilter entry. A text box will appear with the three entries on three lines. Just edit as you would with a text editor.

Unbelieveably both my USB SanDisk card reader and USB Thermaltake external hard drive appear in Explorer (My Computer) and both work normally now. THANKS JOHN MART!!!

*** OTHER STUFF I DID WHICH MAY HAVE AFFECTED THE FINAL FIX: ***
Before I changed the order of PartMgr, Phylock and snapman, I had tried the following which may or may not have affected the final fix:

I have IDE and SATA hard drives as C, D, E, F, G and two optical drives as M and N. Using Blue Mouse's procedure I deleted the DOS devices for drive letters H, I, J, K, L, O, and P. In other words, drive letters that I was not using. I also deleted the Upper Filter statement.

After a restart, the card reader and external drive still did not show up in My Computer. I ran XP's Tweak UI and under My Computer > Drives, the drive letters for H, I, J, K and L were unchecked. I checked them so now all drive letters were checked. I'm 99.9% sure that all drive letters were checked prior to doing BlueMouse's procedure of deleting the DOS drives.

After a restart the card reader and external drive appeared in My Computer. Inserting a SD card in the reader brought up the AutoRun box. I was estatic! But then I discovered that the drive letters for my hard drives were scrambled. Only the C drive retained the correct drive letter. Also in Disk Management, there were NO drive letters for any of the drives and no way to change or assign the correct letters to the drives.

Since I had exported the Mounted Devices and Current Control Set folders from the registry prior to doing anything, I imported both and after a restart my drive letters were back to normal but my USB card reader and external drive had the same problem as before.

This is when I tried John Mart's method of changing the order of the entries in the UpperFilter. After a restart, both USB devices appeared in My Computer and worked normally.

FWIW, my USB inkjet, USB laser printer and USB scanner always worked. But they are permanently plugged in the back USB ports. My card reader and external drive are plugged into the front USB ports.

After so many days and days and hours and hours of searching the web, I'm really happy that I found this thread and got my USB devices working like a champ.

Thanks BlueMouse for getting John Mart on the right track. Thanks John Mart for posting your experience which fixed my problem.

Raptor88

Bluemouse, I registered on this forum, basically to thank you very much for the solution to a very annoying problem.

Thankyou Very much indeed.