external drive hangs computer

Whenever I plug in (to any usb port) a flash drive or other external (hard) drive it causes my computer to hang. Cant use the mouse or keyboard and the only way to get it back is to unplug / replug the computer. The computer power button is even unresponsive. When up the usb will take the scanner, usb cable for the dsl modem or printer. Only the flash or external drives knock it out.
We had a storm night before last. next day i find my internet not working. called insight support and they find the ethernet card is out. The external hard drive was connected, but not on and the flash was not inserted.I disconnected the ethernet wire and went to a usb through the modem.
I have a HP a1320n with XP. Also in the "slot" with the ethernet connection are 2 usb ports and I can not get the scanner, etc. to be seen connected to them. all other 4 usb ports work with everything but a drive.

I have checked the device manager and it shows everything working properly. Has anyone seen this before and would it be easy to fix or is this a take it somewhere for repair? Is it fried and not worth trying to fix?

Thanks,
Larry