screen freezing

Hi:

I have recently been plagued with my screen freezing intermittently. I can be working on a particular site and page, and my screen just freezes. I have to either go into task manager and delete, or click the X in the top corner repearedly until I am back to starting over, and then have to use restore page to get back where I was, only to have it occur all over again. I have run system scans, virus scans, defraged the system, etc. but nothing seems to solve the problem.

I don't have a lot of computer savvy, PLEASE HELP!

Thank you