Getting booted off the internet

I was trying to setup a TechRepublic account for my friends on their computer, ( XP, ie6, 1.10 GH,) they have AOL and can only surf aol. 1. Their system runs very slow. They used HDvalet to clean their disk of junk, but it is still slow. 2. Everytime they try to go to any other site other than aol, aol’s logoff software (saying: Goodbye) disconnects them from the internet. Why is this happening? Help!!!