Enternet 300 DSL & McAfee access

I have Enternet 300 DSL, run on Win/98 and have McAfee Online Antivirus installed. When I try to access the McAfee site for virus updates, the browser, either Netscape 4.73 or Explorer 6.0, rotate between the McAfee clinic login address and the actual home site. I can’t break the cycle to get an update download. Or else, my system tells me that I don’t have an internet connection and askes me to try again or work offline.

I haven’t installed any new hardware or software and this worked right after the initial installation of the DSL software. But, it hasn’t since. How do I correct this problem so that I can keep my McAfee antivirus protection up to date?