I was having a problem where Desktop icon text wouldn't display transparently, no matter what I did... e.g. toggle drop shadows on and off.  Also, Explorer wouldn't show thumbnail views of graphics and pics.  Microsoft had a fix for the icon text transparency problem, but it didn't work for me.

Then I remembered that I'd disabled the Picture and Fax Viewer, and thought I'd see if re-enabling it would help.  It solved both the problems mentioned.  I typed this in the Run... box and pressed ENTER:
   
regsvr32 shimgvw.dll

This command is mentioned everywhere on the Net, just about.  So is this one, which does the reverse:

regsvr32 /u shimgvw.dll

I didn't realize that turning off the viewer would have anything to do with the problems I had.  I'd disabled it before, without this kind of trouble popping up.

Just when I thought I'd have to fix my broken Windows with a reinstall, a clue came out of nowhere and ran into me. :)