Computer locks up when I try to connect to the internet

I would like some help from anyone who knows what I can do
about this problem. About 2 months ago, after surfing the
internet until 3 in the morning, I shut down my PC and
went to bed. When I got up the next day, and turned my PC
on, I clicked on the Internet Explorer Icon so I could
surf the Net again. But instead I got an error message
that said I had to restart my PC.

When I restarted my PC, it forced me into safe mode. If I
chose any other option than safe mode, it would lock up on
me and restart after about 8-10 seconds, starting up in
safe mode.

I thought the problem might have been a faulty Ethernet
Card. So I replaced the card with another of the same
type. Netgear 10/100 etherfast. I have tried moving the
card from PCI slot to PCI slot. I have tried removing the
card restarting my PC. Then shutting it down and
reinstaling the card and starting wthe PC up again for
each of the 6 PCI slots I have. I have triied reformatting
my HD (3 times so far) and reinstalling all the software
from scratch.

Currently, I can get to my dsktop only when my PC is not
connected to the Cable modem. 6 seconds after I connect
the Cable Modem to my PC, the computer locks up and after
8-10 seconds it restarts itself in safe mode.

The line I kept getting is: " rem - By Windows 98 Network -
C:\WINDOWS\net start " in the Autoexec.bat so I edited
this out and it no longer appears, but the problem still
remains. The Netgear 10/100 Etherfast Card shows up in
the System Properties/Device Manager and the Network
Settings, and in the "winipcfg" and I only experience a
cmputer lock up if I physically connect the modem to my
computer. This happens whether I plug it directly into my
PC or into a hub.

Can someone please tell me what I am doing wrong and how
to fix the trouble I am having. the motherboard is a
K7VIB, I have 256MB of DDR ram, a 1.4Ghz AMD Athlon
Thunderbird Processor, and a CD/RW Cd-ROM drive, and I am
using Windows 98 SE as my OS version 4.10.1998

Please feel free to send me your answers to the address
provided, otherwise, I will check back here periodically.
I appreciate any assitance anyone can provide. Thank You.
Bill