This happened during my attempt to load iTunes songs saved on a CD back into a new installation of iTunes/Quicktime Player (the two download/install as a package).
But something did not work as intended. iTunes at first, when I clicked on its icon brought up its empty playlist (library). It let me add one song to the playlist but after that would neither play the song or let me add further songs. All I could do was access the Music Store.
A Repair of iTunes did nothing to help. I then tried an uninstall and reinstall. That did not help either.
Also I have ended up with this oddity: You know how after you shrink a window on the monitor, you can drag it around? Well, I can still do that BUT instead of simply dragging as a entire window, what happens is that an empty rectangle of thin edge lines goes where I drag it. When I release the left mouse button, the contents of the window catch up. This happens with any and all windows.
A reboot didn't cure this.
An afterthought...a repair install of XP sounds like it has a reasonable chane of success. If no less invasive solution, I'll give that a try.
I'LL ADD THE FOLLOWING JUST IN CASE IT MIGHT HAVE SOME VALUE TO SOMEONE.
I was going to wait for a response, but the Repair install idea was too attractive and (as it would not mean reinstalling all my programs) so I ran a repair install. This is the result:
Windows interrupted and restarted the setup part twice. Then it said it "could not load the installer for tape controller. Contact hdwe dealer." I clicked OK; Windows completed its installation and rebooted. Then: "The CinePlayer Decoders have not yet been activated. You must activate the product before use. Please run the player that included those decoders to activate product." I clicked OK. Windows quickly booted (or maybe finished booting) and all my icons were there. Systray icons OK. Windows works as before. Can't say yet re movie files playing.
But the weird problem of dragging screens around on the desktop did not get fixed. It looks as if I'll have to do a clean install. (I didn't know I had a "tape installer"; I've never ever used any tape machine with this computer.)
I fear the only answer now is a clean install of Windows and all my programs. Any opinions or suggestions?