Windows 98 - suggested antivirus program?

Hi - at home I still run Windows 98 (not se) and have had no security issues ever. However, I do want to download some protection and was wondering what programs run well with windows 98 os? I used to run Norton but got rid of it. I just tried Bitdefender v10, but it made my computer run like a slow turtle. I still have the bitdefender download because they may not refund me, but it's disabled right now. Maybe I should just set all the settings at low security? Bitdefender support was not very helpful. I also tried R-firewall, but a popup screen kept popping up every 2 seconds asking about something or another. I really just want some SIMPLE EASY security software to install on pc. free would be better too, although I would like to run the bitdefender if they don't end up refunding me. and yes, as far as I know, I have uninstalled all other antivirus, spyware programs etc (although "completely" removing programs seems almost impossible).

PC has 160 MB RAM, 100 GB hard drive, high speed cable connection, pentium II processor - although how do I find out what mhz the processor is?
thanks!
mbr