Correct. Setting up networks, enabling remote access and even using services like Go to my PC open holes (ports) on your network (router) Firewall and/or PC Firewall that make hacking into your system much easier.
A good secure Firewall is more important then your anti virus software.

Admins, thanks for the help with my mouse. I did not expect to recieve that much info & help!
You guys are doing a great job!!

You're more then welcome.