Internet Stops working after loading avast internet security

I paid for the software and after the initial reboot after the software loads the pc will not browse. We are an isp and the network is up and running. This particular machine runs on windows 2000 professional. I noticed in the device manage that avast loads all kinds of Network interface devices. And even if i disabled all of them except the actual nic card the Internet still will not work nor the network. I have un-installed the product and internet comes back up just fine. Please advise I want to use the software to its fullest potential. Thanks

What version did you pay for? AIS or Pro?

There are issues with Win2000 and the latest MS C++ Redistributable.
Also, you have to have the SP4 and Service Rollup 1 installed on Win2000 for AIS to run.