Disappearing Videos

I came home last night to find a blown fuse had shut off my computer and on restart the screen repeatedly went to black.  The only way I could get it to restart was by going into the BIOS Power Settings and setting "After Power Failure" to "stay off."  This is a recurring problem that I thought I had somehow fixed a couple of months ago.  

However, when I went into my tv program folder, most of the shows had disappeared.  My collection of Deadwood, Sopranos and Oz were all gone but Carnivale remained, though they are all the same file types.  Videos in other folders haven't been affected.  What's more, no memory has been freed up, and a search can't find the missing files.  Norton has found no virus.  

I have Pentium IV, Windows XP.  The files are all on a secondary hard drive (which occasionally is not recognized by Windows on start up).  Other files on the HD are available.  "Check Disk for Errors," reports "Windows was unable ...".  

So what gives?  Anybody have ideas?  Theories? Advice?  

Addendum:  

The same problem with the blown fuse occurred and I couldn't get Windows running, not even after changing power settings.  Had to restart using 6 diskettes.  Any suggestions on what to do about that also would be greatly appreciated.  Word