Help. Windows Security Center acting up

I've recently had a Windows Security Alert pop up on my task bar. When I

click on it, it says I have no Malware protection. I have AVG Free on my

system and it's always showed up before. I also have the default Windows

Defender, in addition to Ad-Aware and Spybot installed. According to Windows

Security Center, no antivirus software can be found on my computer and it

shows Windows Defender is turned off. If I try to turn Windows Defender on, a

window pops up saying it's looking for updates then it can't find any newer

updates but it still never turns Windows Defender on. Something has gotten

screwed up at some point and I haven't done anything to my system or

installed anything whatsoever in recent history that should've caused this. I

have no idea what is causing the problem or what I might do to fix it.

Has anyone else out there experienced any similar issues? If anyone has any

advice, please get in touch with me. Thanks in advance for any assistance

anyone might be able to provide.

Sincerely,

- Byron Followell