I have this same exact problem only I'm running Windows ME. I thought at first it was some spyware or something. I checked with both Spybot and Norton Corporate and that helped none (even tho it did get rid of the spyware). I forgot the exact name of the error message that came up (I had to uninstall just to get my computer to startup again) but it was something like this:

Explorer has caused an error in Shell32.dll. Explorer will now close.

Hopefully this helps alittle. Also for extra info, I'm running Windows ME with a 1.3 Ghz Pent 4 and 512 RAM.