I'd start with the solution in post 4 at http://forums.cnet.com/5208-7590_102-0.html?forumID=67&threadID=52185&messageID=622109
I was getting the USB Power surge message I've read about in a few places on this forum. Instead of turning the message off, I was prompted with some other message (of course I was stupid, didn't write it down, and now I've forgotten what it was). But it has turned off all of my usb ports. I've tried a number of things, including using device manager to uninstall and reinstall usbs, but they still don't recognize anything plugged into them. windows xp. any ideas? thanks.