The two things to do as diagnostics:
1. Try this printer on another USB-port (front and/or back) on this PC
2. Try this printer on another PC
3. Try another USB-device on this USB-port
This will help you to locate the error. That's the first step to repair.
Vista 64bit, HP Laserjet. PC stopped recognizing printer after a power failure. reinstalled drivers, power cycled PC etc. but printer will not work.