network internet problem, please help :)

I just got a new motherboard and cpu (amd 1800+ xp and msi pro2) for christmas, yea. However now I'm having a bad network, internet problem. Here's the deal:

I had win 95 and along with new mb+cup upgraded to win 98se. Everthing works fine except my DSL. I can browse web pages fine for about 3 mins then it stalls for about 30 sec like the connection is interrupted, then it works again. repeat every 3 or so mins. Also I cannot download through my browser. Out of the browser (ie. aimster) it's fine. Then I played a network game of Diablo II with my brother. When I host he gets dropped every 3 min or so. When he hosted it worked fine.

I tried to reinstall win98 and it still happens. A friend of mine said I should delete the windows directory in ms-dos and do a freash install. Does anyone agree with this or have any other ideas? Your help is greatly appreciated.

btw, I have a 512mb ram, big hard drive, monster fusion vid card, and a kingston network card. Thanks again.