System Freezes, when scrolling in Netsca

About 2 months ago, my WIN98SE HP, started freezing up when using Netscape(on AOL)
I thought I had a virus, so I reformatted my HD. At the time, I had called AOL Tech Support around 5 times and they did not know what was wrong.
Now the problem isback again and I still can’t figure it out. I thought it might be a virus, but I am VERY careful what I download form E-mail. Now I think there may be a software conflict somewhere. I had a wireless mouse and bought a wired mouse and that did nothelp ether.

Any help in solving this will be very much appreciated.

Jess