System locks when accessing Internet

I have a Windows 98 System that has been reformatted, it was
reformatted because you could play gameson the computer for hours, but
when you try to get on the internet you get between 10-20 of internet
access then the computer locked up. Lights go off on network card,
monitor does not receive a signal and you have to turn the power off
from the power supply to get it to restart. At first I was thinking
overheating but you can run the system all day just do not access the
the internet. So then Ithought bad network card. Tried a different
one and still have same issue. So I considred driver errors, went out
and downloaded all the latest drivers for every piece of hardware in
the system, reformatted again and stil lhaving the same issue.

Am I down it it just being something bad on motherboard. I even went
as far as to try a different browser in cxase is ws an issues of
memeory useage by Internet Explorer!


Any ideas?