It would be hard to get a virus on a router and doing this for 21 years I doubt you have one.
1) Reboot the router
2) Clean up your computer and run vipre rescue in safe mode.
3) reboot your computer.
You can update your firmware but I doubt this will resolve anything. It does help the router though.
As long as you dont have to many things on your router like forwards or VPN settings you can always reset the modem to factory.
Most of the time in order to get your rig running smooth again you should backup all of your document, songs and pictures and blow it away.
Your antivirus wont help you with malware. Vipre rescue will find it.
http://live.vipreantivirus.com/