If you let Spybot fix Microsoft.WindowsSecurityCenter_disabled,I believe it should reenable the Security Center.When I let it fix mine,it was on Automatic when I checked.If Spybot didn't reenable it,you could try doing it manually.
Shortcut...go to Start->Run,and type services.msc ,then press OK.
or:
Long way...click Start,Control Panel,Performance and Maintenance,Administrative Tools,then doubleclick Services.(that's for category view.)
Scroll down until you find Security Center,then doubleclick it.If it's set to disabled,click the Arrow,select Automatic,then click Apply,and then OK.Then you could click Start,in Start the Service,to start Security Center.
I'm not too familiar with Carpe Diem Vars,but from the description I'm reading it doesn't disable the Security Center,though I do not know that with 100% certainty.
The entry alone is not bad(it's not a virus or malware itself).But it's possible for malware to disable the Windows Security Center,so it's a good warning.
Antivir doesn't disable Security Center,that I know of.
If you feel that Windows Security Center may have been disabled because of malware,(and you're still having problems),you could ask for help in the Malware Removal forum.
The instructions are here:
http://forums.spybot.info/showthread.php?t=288
Malware Removal:
http://forums.spybot.info/forumdisplay.php?f=22
Most people would recommend having Security Center enabled,yes.