Does it print if you use the test print feature within the printer
itself that does not involve the PC -- usually a combination of buttons
or of powering on with one button pressed: check your manual.
If it does not then it would indicate that the printer itself has
failed.
When you installed the XP driver, you did have the USB cable NOT
plugged into the PC as per the instructions for installing drivers when
using USB? Or are you using parallel cable connection?
Since that fails look here in this newsgroup section for a message from
Alan Morris -- "Alan Morris [MSFT]" <alanmo@xxxxxx> --
and ask him for help since he has a very good line into HP's
development people.
If you don't mind I'll ask in my Compuserve PCHardware Forum Print &
Scan section to see if anyone else has heard of this extraordinary
"feature".