The first thing that comes to mind is an MTU issue, which may have been a result of your registry cleaner. I don't know how to fix that under Vista, though. (Actually, now that I think about it, Vista's PMTUD is supposed to be much better than XP's, but I guess it could still be the issue.)

Try this:

ping -n 1 -l 1400 empegbbs.com

Then increase the "1400" by one and try again. Stop when you reach 1600 or a ping consistently fails with a particular value. Let us know what your results are. (Yes, this is no fun. I usually script it under Unix, but I don't know how to do that under Windows.)