Why will my computer not let me restore, run diskscan or defrag.  It has been doing some things I've never seen.  While I was posting this QUESTION it froze up and SHUT down.  Said something about dumping physical memory.  New one to me.  I don' t know what to do next.On the screen that SAYS "Dumping Physical Memory" either write everything down on it or take a picture with a digital CAMERA and post the contents here (yes, even the gibberish letters and numbers)...

Also, are there any other messages that you're getting?  Post those here as well.

Other than that, my only guesses are either
a) Hard drive's about to croak
b) Virus/malware infection.

I'll let a malware specialist handle case b), but as far as a) goes, you'll need to either run some hard drive diagnostics by the manufacturer of your hard drive or boot into the Recovery Console or WinPE and run CHKDSK against the drive.

Before I or anyone else posts any instructions, we do need error messages and all that good stuff from you, though.Open Windows Explorer.
Navigate to: C:\Windows\Minidump folder.
If you see any .dmp files, zip all of them, and attach zipped file to your next reply.
Vista users. You MAY need to copy .dmp files, paste them into some other folder, or desktop, and zip them there.