Found with http://www.google.com/search?hl=en&source=CNET&q="Windows+98"+ANTIVIRUS+FREE+SOFTWARE this is free and will catch the usuals.
Now about the firewall. On DOS and DOS based windows that's optional. Lost discussions about why.
I inherited a pc that runs Windows 98...when I try to download Avast antivirus software from CNET, I have problems....I am immediately taken to the CNET help page........I currently have no antivirus software, and I want to run anythimg that works....any ideas?