Recently my friend tried avg antivirus. after a few days she was unable to get online and her screen was mesed up.

I un installed avg, cleaned her system and put on norton av. everyhings been working fine until today. when her screen only filled the last 3/4 of the screen. I found it was due to a file not loading properly from norton.

I reloaded norton and the dsl works for 10-20 minutes and then nothing. can anyone help me. FWIW she is on verizon dsl