Has this just started happening all of a sudden? I haven't had any experience of this, but a few people have & it seems to often be due to downloading a corrupt file. Have a look at the threads below & also use the forum search to look for explorer close, or something similar.
http://www.gnutellaforums.com/genera...ed-folder.html
http://www.gnutellaforums.com/open-d...ewire-exe.html

If you can remember what you downloaded just prior to this happening, delete that file & see whether it helps.

It might be a good idea to make sure your AV's up to date & scan your computer, just to be on the safe side