I recently tried to connect a canon G1 camera to my pc (AMD1.1GHZ / Abit kt7-a, 768M ram, Win XP pro) thru it's on board USB port. When I did as instructed, I lost my USB mouse and keyboard (and my USB controller for all I know). I disconnected the mouse and k/brd and tried again but there is no recognition by XP of any USB device, Control pnl. indicates usb is functioning, so I took the mouse and k/brd and tried to install them on my other pc in both usb and ps/2 mode. They don't work in either.
I fear that the Canon G1 sent a fatal voltage thru the usb system and killed the two devices and likely thr controller too.

Can anyone give me advice on how to check to see if this was the case, using meters and reference voltages to confirm one way or the other?