Safely Remove Hardware

By blue3 · 20 replies
Nov 6, 2004
  1. When you connect USB device to the pc it instructs to turn your device off before removing it - Safely Remove Hardware. How risky is it if you forget to turn the device off before plugging it out? Does anyone ever experience ending up damage to the device?

    I sometime forget to do click that icon, just want to know if is really important to turn it off. Btw does anyone know the electronics behind this?
  2. Spike

    Spike TS Evangelist Posts: 2,168

    Usb sockets, from the moment they are activated when you boot your computer, carry a constant 5 volt supply. For this reason, although not reccomended, if you plug a usb device in while the computer turned on, holding the connector loose at the front of the socket and slowly pushing it in, you will see small sparks on occasions if you look closely.

    Whether or not it is particularly dangerous in terms of hardware damage to plug and unplug usb devices while the pc is on... well, I guess it depend on the device. Generally speaking, it's pretty safe, but I wouldn't like to guarentee that EVERY usb device is hot swappable.

    Of course, I'm only speaking on theory from what I know and what I've seen, but personally, if I'd just spent £300 on some delicate piece of USB hardware, I'd try to avoid the power surge, however unlikely it was to damage it. If it's a gamepad or a mobile phone (cellphone) charger, I don't really care.

    One thing I do know though, is that unplugging or replugging USB hardware while the computer is on running windows does sometimes crash the OS, producing a BSoD with a stop message mentioning (usually) USB related files. It doesn't seem to happen all that often though. I'm not 100% sure, but I believe it happens when a device is in use when you unplug it, and using the Safely Remove Hardware function ensures that the device is not in use so that it can be unplugged without crashing windows.

    Hope this helps. Any little inaccuracies will be corrected I'm sure.
  3. Didou

    Didou Bowtie extraordinair! Posts: 4,274

    For an USB storage device, it can be dangerous if the device was in the middle of an I/O command when you unplugged it. It can go from corrupting a single file to the whole filesystem on the storage device.

    For other devices like webcams, modems, etc. the risks aren't as obvious.
  4. Nodsu

    Nodsu TS Rookie Posts: 5,837   +6

    By default write caching is off for removable drives in Windows. So when you unplug your USB storage device then the worst that can happen is losing (some of) your data through filesystem corruption only if you unplug during a write operation.

    I only have experience with flash sticks and those can be unplugged with no problems if you don't have any writing to the disk happening.

    I think that people who make USB devices are smart enough to take the general stupidity of users into account and make sure there is no physical damage to the equipment is someone unplugs it.
  5. lilyiann

    lilyiann TS Rookie

    I have a similar problem and and the computer immediately restarts after a blue error screen appears (i'm using xp home). I think it's because I don't click the safely remove hardware. However, now the problem's getting worse. Last time when I installed SP2, the error occurs everytime I turn on the computer (the windows screen), even before the log in screen. Then I uninstalled SP2 in safe mode and the computer was normal again. However today the same problem happened again, when I turn on the computer before the login screen the error occurs and I'm in safe mode. How do I fix it ?

    BTW the error report I had before said :

    BCCode: 100000be BCP1: F9F6D6AD BCP2: 034A6121 BCP3: FA2D3DD8
    BCP4: 0000000A OSVer: 5_1_2600 SP:1_0 Product: 768_1
  6. mejensen1

    mejensen1 TS Rookie

    a spark flew

    About 4 years ago, I was working on my self assembled PC; it had Win ME a 900 mhz Intel cpu, and an Intel built mobo. I wanted to reboot, but sometimes had problems when it restarted with the $10 USB keyboard and mouse, so with it on in its big medium tower tooless case, I pulled both the mouse and the kb connectors which were attached adjacently. The pc immediately died. I took the cpu to a computer store and it was tested dead. I tried a working cpu in the mobo, and it also didn't work.

    I had a three year warranty on the mobo, so Intel replaced it. I only had a 1 year retailer/OEM warranty of the cpu chip and it has just passed. However, I used a Visa CC, so Visa paid for a $120 1 Ghz chip because the 900mhz wasn't available anyplace. However, I never reassembled the parts once I got them. Completely self built pcs are a pain, whereas ungrading can be satisfying sometimes. Anyway, I am going to ship all these parts and others to my nephew in California from my abode in Seattle, to see what he can do with it.
  7. Sharkfood

    Sharkfood TS Guru Posts: 1,019

    This is mainly protection for USB storage devices. Sometimes due to cache or otherwise, an I/O or write to the device isn't truly completed instantaneously.

    So, for example, if you're dumping like a 200mb file to a USB stick.. and the file copy wizard with the paper hurling across two folders completes.. it might be 2-3 seconds after the wizard goes away before the operation is truly completed. If you just yank the stick the moment it completes on-screen, you might have a partial file or corrupt file on the stick.

    Most everything else.. I prefer dangerously removal of hardware. After running with scissors, playing with matches and wiping back to front, I'll lick my fingers while pulling out usb devices and make sure I'm standing barefoot on moist carpeting.
  8. Nodsu

    Nodsu TS Rookie Posts: 5,837   +6


    I have a USB stick with metal casing and sometimes when I try to unplug it, the static discharge makes the computer power off immediately.. So usually I pull from the neck strap or touch the computer case before.
  9. gbhall

    gbhall TechSpot Chancellor Posts: 2,431   +77

    You are electrifying !!

    Nodsu, for someone of your experience not to do something about static is odd... at least change your carpet from polyester to wool !

    Actually, it is quite well-known that people vary widely in the amount of static they hold in their body. People who sweat a lot probably have more salt on the skin, leading to higher (or lower) conductivity. Some people can yank a memory chip out of a mobo without a care, other will blow memory almost by just looking at it.

    All this is a bit out of the way, when we are talking USB, all the above posts are quite correct, but it would certainly make a difference if you were fully charged-up (like Nodsu !)
  10. Nodsu

    Nodsu TS Rookie Posts: 5,837   +6

    Well, it's quite hard to tell people "I aint doing anything with that computer until you change your floor covering!" :p
  11. gbhall

    gbhall TechSpot Chancellor Posts: 2,431   +77

    depends who needs to be told!

    If it's your better half, I might agree, but if it's your client and there is a clear possibility of static discharge due to floor coverings, then I would most definitely regard it as professional behaviour to advise the client of a way to save himself a lot of potential grief.
  12. Hatrick

    Hatrick TS Rookie Posts: 90

    Carry a rubber mat.
  13. Sjbrand99

    Sjbrand99 Banned Posts: 260

    Thats not the only rubber you should carrry... ;)

    ... also carry a rubber anti static wristband.

  14. Hatrick

    Hatrick TS Rookie Posts: 90

    You must be lucky in your choice of clients but , just in case, maybe a rubber cosh (sap?)too?
  15. SNGX1275

    SNGX1275 TS Forces Special Posts: 10,742   +421

    In my expierence/opinion there is nothing wrong with pulling the USB stick out without letting Windows know, at least nothing wrong with the stick. I've seen windows go wierd (restart/shutdown) before but that may be related to static like Nodsu says. And of course you shouldn't pull the thing out while windows is writing to it.

    One thing that is interesting is in Windows if you tell it to safely remove the light on my usb stick goes out, but in OS X if you unmount it, the light stays on. I think this further indicates that there is no damage done to the usb device by unplugging it when you feel like it.
  16. gbhall

    gbhall TechSpot Chancellor Posts: 2,431   +77

    on the subject of static...

    I'm not too worried about continuing the subject of pulling USB memory by moving on to the subject of static electricity. It must be clear to anyone who ever studied physics that (a) microcircuits must be incredibly sensitive to static (b) CPU designers must take extreme measures to protect their circuits from static (c) the vast majority of users will be ignorant of potential problems (especially in my country, which has almost totally given up the idea of education in physics for the current generation)

    In a few words - make sure your PC is earthed through the mains. This is standard in Britain, I am not so sure about other parts of the world, where 2-pin supplies might be normal.

    Be aware that rubbing your hand on nylon or silk can generate 30,000 volts or more, albeit at minute currents. If you dont believe that, try it in the dark and admire the flashes).

    Computer cases made of metal are going to be inherently better than plastic cases (note Nodsu touches the case first, to earth himself).

    I must wonder just how many of the 'sudden failure' cases dealt with on this site can really be put down to static discharge from people standing on a nylon or propylene carpet who then touch a PC which is not properly earthed through the power cable?
  17. quixilvr

    quixilvr TS Rookie

    I found an amazing program that allows you to quickly remove the USB devices that you commonly use called RemoveDrive. I found it when I was researching some of the other program alternatives like "USB Safely Remove" (which is shareware and has an annoying popup screen) & "DevEject" (Which is another command line excecutable like RemoveDrive, but it does not remove drives considered as "Local Drives").

    RemoveDrive is a command line executable, so you would need to tell it what to remove drive by drive. I saved the RemoveDrive.exe to "C:\Program Files\RemoveDrive" and then created a BAT Batch file with the following:

    CD C:\Program Files\RemoveDrive
    RemoveDrive.exe "Simple Flash Disk 2.0 USB Device"
    RemoveDrive.exe "Multi Flash Reader USB Device"

    The device names in quotes are the names of my USB devices as they appear in the "Safely Remove Hardware" >> "Stop a Hardware device" screen that you would normally have to use to remove your devices. Now I have the Batch file assigned to a "Hot Key Plus" combination, and I can remove my USB drives in a flash!

    You can get the RemoveDrive.exe file at:

    Hope this helps
  18. Sjbrand99

    Sjbrand99 Banned Posts: 260

    Whay dig up this 3 year old thread to say that?
  19. SNGX1275

    SNGX1275 TS Forces Special Posts: 10,742   +421

    Last replies before his post was from Dec 2006. So its been fairly recently discussed. You even posted in this thread, Post #13, on December 4th, 2006.
  20. Sjbrand99

    Sjbrand99 Banned Posts: 260

    **** off SNGX
  21. dement0r

    dement0r TS Rookie

    I have never, not once, used "Safely Remove Hardware" to remove any type of USB device, and have never experienced any problems. I usually make sure that i dont have any files open that are on the device, but sometimes i have left them open by mistake and they have just closed themselves, but no damage has been done to the device. If you ask me, the function is pretty useless, since i've never used it and never had any problems due to not using it.
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