Vista - IE dropping connectivity under Vista

Vista Home Premium Internet Explorer Problems

I frequently loose connectivity to the internet while reviewing a long BB
posting or inactive for long periods. The only way to get reconnected is to
restart my new HP 7760 PC. Meanwhile my wife is Happily Surfing the internet
in the kitchen on her new iMac 20. We are both on the same LAN, behind the
same router that is connected to the high speed cable modem. My cable
provider has thoroughly tested my connectivity twice and has found it to be
in perfect working order!

Ads on a bulletin board post “can not display messages� as I am read
postings without a connection problem.

Installed programs that require constant data communication (Charles Schwab
Street Smart Pro) Cause a “do you wish to continue� even though my ID has
administrator authority and I clicked start with administrator authority.

When I click on Explorer Page/View Source, a security message comes up
saying a Website wants to open code.

Security on my PC is way out of order, question is, how do I fix it? At
this writing, I am not using windows Fire wall or defender virus support. I
am using Webroot Spy Sweeper, Trend antivirus software and router firewall.
Where do I go from here? JP