Internet is fine. I start browsing, and it goes down. Solution?

Windows 7, 64 bit. Connected through router. Internet works fine. There are downloads and updates going on, no problem. The moment I start browsing, everything goes down and there's no browsing or downloading or any activity. It remains this way for a few minutes then comes back up. It keeps happening over and over again.

I'd really appreciate any help I could get for this strange problem.

 

Define "browsing", I assume you mean in your browser? Which browser are you using? Are you using wireless? Which model of router? How old is your computer? You can also see if maybe updating your network adapter would help.

 

Firefox and other browsers too. No wireless. Computer iss months old.

Thanks for the suggestions. What are these hallmarks of? That is, when the internet goes down as soon as someone starts browsing? Malware? Hardware? etc.? What's the most likely culprit in your opinion?