1. You have viruses and spyware. Go to
http://housecall.trendmicro.com and get a free online scan. In addition to updating and running Spybot, install, update, and run Ad-Aware.
2. IE6 and Windows 98 is a 50-50 crapshoot. I recommend you revert back to IE 5.x, if you do an add/remove on IE6, choose the "restore previous configuration" option.