Your post is very light on details. No OS mentioned and more.
In short, is the machine free from parasites? Read http://www.doxdesk.com/parasite/
And try this. Remove the case cover to sniff out if it's a heat issue.
Bob
This is my problem: I use Internet Explorer 6.0. After I have been on line for just 3 minutes, I can no longer access any web site. I get the message "this page is not available". Meanwhile, I still have my Netzero internet connection. I try Netscape Navigator. I have the same problem. Please, help me.

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