USB device causes computer to freeze

I run Windows XP, whenever I connect my WD USB hard drive or a pny 1 gig memory stick the computer freezes. The bios is set to allow windows to manage it and it happens on all 4 usb ports of the machine. If I try to boot with the device connected, it will not boot. Other usb devices such as printers and cameras work fine. The memory stick is the only usb device connected when this occurs. Any help would be appreciated.
Thanks, Chris
geckoevan@sbcglobal.net