Running XP Home, SP2 w/1 gig.  All of a sudden my machine is beginning
to do strange things.

First of all my second hard drive (D:) disappeared...it didn't show in
My Computer.  "Add New Hardware" didn't bring it back.  Then, all of a
sudden it was back.

Secondly, something changed my screensaver, but I was able to restore
it the usual way.

I've used Registry First Aid to check on registry content, and, I've
run a virus scan (NAV) and I've defragged the drive.  Also, neither
Counterspy nor Spybot could find anything wrong.

Anyone have any thoughts?