I have had this issue before and did a clean install. That seemed to fix the problem but this time I want to fix it without reformatting since it has happened twice already and I don't want to lose my files again. The problem is that my firewall was randomly
disabled after I got done playing GTA IV and I tried to turn it back on but I got an error (Action Center Cannot Turn On Windows Firewall.)
After that I looked under my services and found out that Windows Firewall was Disabled and so was Internet Connection Sharing (ICS)
I tried to enable both of them with no luck, I get this error when I try to enable ICS.
http://i55.tinypic.com/w7ebgw.png
I have ran a virus scan with ComboFix and tried to use a RootKit scanner provided by Kaspersky and found nothing. Any help trying to fix this?