Some motherboards/bios setups will do that when USB printers and such are connected and turned on. If that's the situation here, then you might try browsing the BIOS for an item called ?Legacy Support?, then disable/turn it off. then save your changes - reboot. After rebooting into windows, plug in your USB device, then with it plugged in, reboot - it should work fine.This is a fix for many usb devices especially printers which contain on-board computers.

Hope this helps.

Grif