Windows 7: Security Centre disabled, Windows defender missing.

Having been hit with a virus or malware just recently, I am not quite sure whats going on.

First I noticed my Security Centre was not running and the windows firewall was deactivated. Normally this job would fall to my Trend Micro Titanium Security, but that seemed to been disabled also. Which I thought

I managed to install avg 2012 and malware bytes to try remove any bugs. AVG picked up a few issues and fixed them, but all further scans came back clean. Unsure if the issue is solved, the problem of Security Centre still being disabled remains.

I've tried the service.msc technique several times to no avail as the security centre just wont start and Windows Defender is no where to be seen.

Windows Defender Error: "the specified service does not exist as an installed service. (error code: 080070424)

I know this is vague, but I'm at the end of my rope. If additional information is required, Ill be happy to provide them (with necessary steps to reveal them).

I'm currently running Windows 7 - Home Premium 64bit OS.

Windows Firewall damaged by 'Windows 7 antivirus 2012'

Error Code 0x80070424 with Windows Firewall and "Base Filtering Engine Service" Not available in services database list. - Microsoft Reduce Customer Effort Center - Site Home - TechNet Blogs