Two snide responses:
1. Install the hardware it has found.
2. Never shut down the computer.
A more reasonable answer:
- discern what hardware it has found
- possibly download the latest drivers for it
- install drivers or tell the wizard where they are.
To determine unknown hardware, right-click My Computer and select Properties. Then find and click Hardware Mangler. Look for devices that have a yellow '?'; this will be a good clue as to what needs to be installed. There is a slim possibility that you will need the mfr's drivers for your motherboard.
That said, I have had XP insist on installing my printer every time I turned the computer on. I think it was my HP Color LJ2500. (But as I recall, every time I installed it, it *always* said it encountered a problem and couldn't complete the install; thus it would retry every time I booted the computer.) The only way to fix this *might* be to unplug the device, uninstall the software and drivers for the device, delete the printers, delete the printer device and start over.