Need some help please

One of my home computers is having a major problem with its internet connection. I have made absolutoly sure that it is not a hardware problem. The network connection works, other computers connect as normal so its not a bandwidth or service problem, and I can even ping web sites but there is somthing that is hindering my software from doing the job. I have Netscape and Mozzilla browsers. when I boot the machine up it works fine and AIM along with the browsers are fully functional. But after several seconds the browser slows down greatly i have cable and have concluded by using other machines at the same time it is not the cable it is the one computer. After several minutes the sites stop loading completely and nothing comes up on the browser except the "done" text, it doesnt even start to load a page no matter what browser I use it does the same thing. Yet the network connection is unchanged, and AIM is still up. It seems only several programs are effected. My computer is protected by Mccafee Virus Scan, and Ghostsurf 2005 platinum (all updates in effect) and is running Microsoft Windows XP proffesional. I have found no spyware nor a virus responsible yet there may still be.

Also I don't know if this has anything to do with the above problem but there is a program running in the background that I can locate the exe for and the regestry value but it regenerates when I attempt to remove it. The file takes up considerable ram and has no purpose of running, also it runs several times at once. It is called yRyQ.exe does anyone know what that is?

Thanks