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I'm trying to troubleshoot a problem a friend is having. Her keyboard suddenly stopped working. She had a wireless keyboard/mouse combo and the mouse still worked. She tried with a different usb keyboard, and it still didn't work. She tried with a PS/2 keyboard and it didn't work.

She's running Windows 7, but the keyboard also doesn't work during boot-up.

I've got no idea what could possibly be the problem. Any suggestions?

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have you tried the original keyboard on another computer? just to prove the keyboards themselves aren't the problem here. – quack quixote May 11 '10 at 12:11
What's the BIOS/What model PC is it? Is it a custom built? Is it a pre-built? If it's a custom built, what is the Motherboard Manufacturer? – George Stocker May 11 '10 at 14:13
It's now fixed. There was a bit of miscommunication between the two of us, she didn't try a second USB keyboard, only a PS/2 keyboard without rebooting and it didn't work. I told her to try the PS/2 keyboard again and reboot, and it worked. It seems that the USB keyboard was broken. Thank you :) – Adrian Mester May 11 '10 at 21:00
up vote 2 down vote accepted

With PS/2 Keyboards, you must reboot the computer after you plug them in to get them to work.

They are not designed to be 'hot pluggable'.

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I quote: "She tried with a different usb keyboard, and it still didn't work.", "She's running Windows 7, but the keyboard also doesn't work during boot-up." Which leads me to the conclusion she has already tried rebooting! ;) Your answer checks out though! – BloodPhilia Jun 16 '10 at 16:15
this isn't really true anymore with most motherboards. if the BIOS detects a keyboard at the ps/2 port at boot, it puts power to that port, otherwise the port remains powered down. if you've booted with a ps/2 keyboard plugged in, you can hotswap them all day long. if you didn't boot that way, you do (probably) need to reboot to get the ps/2 port turned on. not all motherboards work exactly like that; i have one old P2 system that always turns on the ps/2 port at boot, so hotswapping ps/2 is always possible. – quack quixote Jun 16 '10 at 16:41
sorry I didn't update, but problem was solved and that was actually the the issue :) I misunderstood, she didn't try it with a usb keyboard, just a ps/2 one and she didn't know she had to reboot :) – Adrian Mester Jun 17 '10 at 10:25
@Quack Do you have any sources for your information? Everything I've dealt with (I'm a DIY'er with building gaming rigs as far back as the mid-90s) suggests they aren't hot swappable or pluggable. – George Stocker Jun 17 '10 at 12:08
@George - I have to say that on newer mobos, I've had success hot plugging PS/2 keyboards even when only USB was attached at boot. In the early days, that definitely didn't work. A couple years back though, someone said "hey, why do you shutdown/reboot when you do that?", and I tried without and it worked fine... Still a good idea though, the PS/2 bus really wasn't designed with hotplug in mind... :-) – Brian Knoblauch Jun 17 '10 at 12:43

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