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According Microsoft, "Universal Serial Bus Devices Do Not Work in Safe Mode" under XP. However, in my testing this is incorrect. USB keyboards, mice and flash drives seem to work fine in safe mode (I made sure the BIOS was not providing support). This makes sense because a failure of a standard input device would be, in Microsoft parlance, a "bad user experience".

So, Is USB supported in safe mode on XP?

  • If your answer is no (agreeing with Microsoft), please provide a test case, preferably in a virtual machine, where a standard HID keyboard or mouse fails. Please state hardware / BIOS / OS configuration. Note that you will need a PS/2 keyboard attached in addition to your USB device(s) in order to use the boot menu. Virtual machine software usually emulates a PS/2 keyboard. Alternatively, you could add the /safeboot switch to boot.ini.

  • If your answer is yes, please provide a link to some supporting documentation (either from Microsoft or someone authoritative).

Your answer might be "devices X, Y and Z are supported but nothing else", in which case also give a link.

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Boot into Normal Mode with PS2 keyboard/mouse. Uninstall all of the USB-devices, make sure USB-support is disabled in BIOS and then try Safe Mode. – Volodymyr M. Nov 13 '12 at 11:50
Seems that USB Keyboards/Mice/flash drives have native Windows OS support, while the USB game controller requires a driver that wouldn't be loaded in Safe Mode. – Bon Gart Nov 13 '12 at 16:26
@BonGart right. Which contradicts the MS article - I wonder if there is some "more correct", official documentation somewhere? – Hugh Allen Nov 13 '12 at 21:05

My answer is "yes" and I'm going to use the registry from a regular retail installation as my "supporting documentation", as I can't seem to find a link to a Microsoft article stating this officially.

For safe mode, Windows will load the drivers/device classes listed under the following key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SafeBoot\Minimal

On my test machine, I see device classes in there for USB controllers, human interface devices (KB / mouse), and disk drives. So, based on what I see there, I would expect a keyboard, mouse, and flash drive to work in safe mode.

Furthermore, I think you are misinterpreting the Microsoft KB article. I think the title refers to a specific problem scenario where the BIOS does not support USB, or the option is toggled off. The article is not stating that there is no USB support in safe mode.

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This is an old question talking about XP, and this could have changed in more recent versions. Just to confirm, your answer applies to XP? – fixer1234 Mar 3 at 0:54
Yes. Furthermore this is also true in W2K, Vista, and 7. It appears to exist in 8.1 and 10 but I'm not sure if it's still referenced. – BrianC Mar 3 at 1:12
Since the mouse/keyboard would work if either the the operating system supported them directly, or the BIOS supported them by emulating PS/2 peripherals, and the KB article specifically mentions USB legacy mode, I am pretty sure I am not misinterpreting it. – Hugh Allen Mar 3 at 12:18
The article states "Windows XP does not support the use of a USB keyboard or mouse in Safe mode unless the computer BIOS supports these devices." If you are turning on legacy mode then you're essentially turning on BIOS support for the devices. If your BIOS is newer and has native support for USB devices, you're not going to have this problem. If your BIOS is older and this option was turned off, it's possible that you wouldn't be able to use them. I'll grant you that the Microsoft article might be making blanket statements but the original point still stands; there is USB support in safe mode – BrianC Mar 3 at 17:29

Your USB devices work in Safe Mode because USB support is enabled in BIOS. If you go to "More Information" section in MS article, you will find the next statement "..In the case of USB input devices, in order for them to function in Safe mode, the system must have a BIOS with USB support for input devices and USB legacy mode must be enabled."

Thus, to make your USB devices to work in any mode, you need to enable USB support in BIOS. If this option is not available, try upgrading BIOS to a newer version.

Enable USB Support in BIOS explains how it can be enabled.

share|improve this answer
You seem to have misunderstood. I know about USB support in the BIOS and made a point of turning it off as I said in my question. I have been unable to get mouse/keyboard to fail in safe mode, and I'd like to know if that is possible. If it's not possible I can throw out my old PS/2 peripherals. You haven't tried this yourself have you? – Hugh Allen Nov 13 '12 at 10:26
-1 for ignoring the questioner and not answering him – barlop Jan 3 at 6:03

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