Originally Posted by GeorgeK

Assuming you're on a cable modem or DSL, it is best to get a hardware-based router, and then place that between your computer and the internet. You'd be able to also share the connection. Assuming the router is setup properly, those scans would be of the router, and not your PC. A router can be had for under $50 these days.

You can do a quick scan of your PC from the internet via "Shields Up" at:

http://www.grc.com/

On my router, all ports are closed, so the scan shows no vulnerabilities.