Hi,
This is kinda my last chance for an answer on this weird problem. I know its a long story but I hope to narrow down everything I tried.

I was using my computer last nitgh and suddenly the computer started randomly disconnecting and reconnecting my Keyboard. It gave me the "new hardware found and connected noise" and also right after it the disconnected noise. I rebooted the computer and had the same problem. I pulled the power lead out and also held down the power button to drain the thing and still nothing.

As the mouse was still working, I tried the keyboard (USB) in the mouse slot and it still didnt work. I even tried a different keyboard with the PS2 connector and nothing. I took my keyboard and tried it in another 3 computers and suddenly, those computers started doing the same thing.

Even on boot up I cant get into the bios because my keyboard doesnt work so i assume its not a driver fault as nothing is loaded. Only when i pull the wire kind of tight at the back does it work but if it was a mechanical fault, why done I have to pull the mouse tight in the same slot for it to work? So I assume all slots work, but any Keyboard I tried (4 of them ) does not work.

My Girlfriends computer worked last night with a keyboard (finally) but this morning it stopped yet again.

I scanned all computers with an up to date virus checker and nothing also.

Any ideas??

Thanks guys.

Very strange.

I have never heard of anything similar, i would guess it is hardware problem but I cant figure out how that could be or how to test it as it sounds like you have done most tests.
First I am pretty sure there are no viruses that could store them self on the keyboard and then install on those other computers that you tested.
So that leaves that the keyboard in some strange way, causes the issue.

Ok, first thing i would try is to reset bios and see if that has any effect.

If it is an old keyboard I would throw it away and get a new one. Probably not going to help but it seems to be the culprit and keyboards are cheap

Please keep us posted if you find the issue as it is by far the weirdest thing I have ever heard of

Retire it Quickly...

It seems like the offending keyboard might have a short circuit, if so I would really not continue to plug it into other machines. It sounds like there could be issues where the cord enters the case. (strain injury?) If the BIOS is set to recognize a USB keyboard this could possibly be why it's ignoring the PS2 port.