Lost IE and Outlook Express connection

[redito]

A friend suggested I look for help here.

My internet connection drops out after about 15 mins if I don't keep
refreshing or loading new pages or checking for new e-mail. Anything
that doesn't need an internet connection keeps working fine on the
computer.

It's a new system running WinXP with all the patches. It was working
fine until Sat.

My ISP - Shaw - says the modem is fine and it is giving them no error
messages. An ipconfig when the problem occurs shows a valid Shaw IP
address. We deleted Winsock and rebooted but that didn't help
either. I didn't install or activate anything for at least a couple
of days before the problem occurred.

I had a Linksys router (wired) installed but disconnected it because
my ISP figured that was the problem. It wasn't. Haven't reconnected
it yet.

I'm running System Suite 8 and using their firewall and AV. But even
if I disable both of those the problem still reoccurs. A reboot
always solves the problem temporarily. Nothing else seems to.

If I let IE hang for a while it returns the message that the web page
can not be displayed. Sometimes I get an error saying windows can't
find an IP address. If I use the repair option it still can't find an
IP address.

I took the CPU back (since it's new) and had the tech check
everything. No hardware problems, no viruses they or I could find,
nothing. And they couldn't reproduce the problem. But they are
working off a network using a setup different from mine.

I figured it was probably an XP corruption or glitch somewhere. And I
read some other messages similar to this but they were about wireless
networks or problems a bit different than mine.

Any help would be greatly appreciated!
Thanks!

 

[redito]

An update.

I thought that by keeping my e-mail running in the background checking
for new messages every 5 minutes that it would keep my connection
"live". But last night it timed out on me again despite that.

Any help would be really appreciated!!
Thanks.