windows security center is turned off

Issue 1: 

security center service can't be started

Solution: 

Issue 2: 
can't turn on windows firewall  under security center

Solution:

http://support.microsoft.com/kb/920074

http://www.thewindowsclub.com/windows-firewall-service-does-not-start

http://www.sevenforums.com/system-security/253751-windows-firewall-service-won-t-start.html