Windows Security Center is where you check the status of your registered firewall, AV, and other security tools. It does nothing protective on it's own. You only mention that it says it has a problem but you don't indicate what error message it gives you.
Also, since Windows Security Center was removed from 7 (and I believe Vista as well) if you are running one of those it is almost certainly a virus masquerading as the security center.
P.S: it's practically illegal for Microsoft's "Right hand" to know what it's "left hand" is doing. MSE cannot- and does not- do anything that a normal AV program cannot do, integration wise.