I have Microsoft Security Essentials and I have all the settings where they are supposed to be so I do not understand why I am having the problems that I am having.

I have this problem every couple of months my firewall turns it self off and i can do a full scan and even update my stuff and the firewall still does not turn back on?

To turn the firewall back on I have to uninstall the Microsoft Security Essentials and then re-install Microsoft Security Essentials to get the firewall to turn back on.