Did they offer to sell you a copy of XP as well? That's a load of horsecrap. Until 2 months ago I had been using my old 98 machine, original version, not the updated 98, because my XP machine blowed up, and it ran just fine.
You have some kinda spyware browser hijacker screwing you up. If all you have is McAffee you probably have a couple dozen virus crawling through your machine as well. Some backdoor trojans. Probably got some goob in China using your machine as a spambot. If you don't have your HOST file locked down, a firewall, spyware detection/removal software, along with quality virus protection you might as well throw your machine out the window into a ditch. And that's just the beginning of securing a computer. When was the last time you ran update on your computer? There were a ton of security updates for 98 as early as 2 months ago.
Some folks did a test recently. Took a newly formatted machine, hooked it to the internet, and it was blown up with trojans and virus' in less than 10 minutes. And they didn't do anything but connect to the internet.
Your best bet would be download a firewall, updated virus protection, and other modes of anti-scumbag weaponary on a secured system, burn it to a CD, full format your PC, and start over. And get it secured before you connect to the internet.
Try out the steps at this link
http://www.dslreports.com/faq/8428 and see what you find.
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