Device Manager Locked up following SP 2 update

Hi, don't know if anyone else has had this problem but a week or so after
installing SP 2, my device manager and anything controlled by it has stopped
working. My USB ports, plug and play, printers, sound card all no longer
work and I can't even get into the device manager anymore to even see what's
going on. In control panel, I get to hardware and click on device manager
and the page comes up but it is completely blank. When I try to print, I
receive a message that the printer spooler is not running and that no
printers are installed. My audio will not play and when I try to adjust the
volume, I am told that no sound card is installed. I have a Dell Dimension
4300 about two years old. Tried to reinstall XP but got a message that the
version on my computer was newer than the version on the CD so it wouldn't
let me proceed. HELP!!!

Thanks
--
Total Loser