Well OK, I skipped over this thread, opting to offer no help at all rather than tell him he's using the wrong program which is what I normally do, but I guess since it's something we seem to unanimously agree on.... don't use BitComet, use μTorrent
If you insist on BitComet, I honestly have no idea why it won't run for you. I assume you've checked to be sure the version you downloaded is compatible with Windows 7?