I suggest that you take advantage of the free scan from Microsoft:
Windows One Care Free Scan
Go to Windows Live Onecare Free Scan
It will say "Get a free PC safety scan"http://safety.live.com/site/en-us/default.htm
Make sure you click "Full Service Scan"
in the middle of the page and not the "Try It Now Free" on the right side.
Allow it to download an Active X component.
Choose "Complete Scan" in the window that opens
Do not click on anything else that offers you a free trial or to sign up if you live in the US.
Allow it to scan - it may take quite a while, maybe two hours or so depending on how big your hard drive is and how fragmented your registry and drive are.
What version of Everest do you have?
V 1.51 has a software module which will tell you what programs are installed on your computer.
If you have a later version, uninstall it and get V1.51 from the utilities section of oldversion.com
Look for a third party firewall.
The problem with the Windows firewall being disabled if you do not have a third party firewall is that your System Restore function may also be turned off. Check and see if it is functioning.