Solved Windows Defender error code Ox80070424

[shjack26]

In attempting to fix my email display, I discovered Windows Defender is not turned on, and cannot be turned on. I have looked for MSE in my Programs list and don't see it. In addition, when I click on Windows Defender in the Control Panel, it shows its last scan December 12, 2011- 1 year ago.

I do have the Windows 7 Home Premium Install Disc. Can I just reinstall Windows 7? If so, what prep do I need to do?
If I do that, do I need to search out any malware, viruses, trojan etc?
Another option is to install MSE, but I may not be looking in the right place to see whether it is in fact installed, and has turned off Defender.

I did have the trojan horse: trojan.win32.agent.hip 2 weeks ago, but the tech help at StopSign/eAcceleration which is my virus protection said this was a false positive. It was caught by Stop Sign and quarantined.

I also run Malwarebytes and all scans are clean.

 

[Layback Bear]

Please read this.
Encyclopedia entry: Trojan:Win32/Agent - Learn more about malware - Microsoft Malware Protection Center

I don't think much of this Stop Sign Antivirus program.
Some questions.
1. Do you want a clean install?
2. Do you want to check your computer for infections and clean them out?
My suggestion would be a Clean install because who knows what this Stop Sign program has done to your computer.

 

[AddRAM]

You could try running windows defender offline first.

http://www.sevenforums.com/tutorials/166445-windows-defender-offline.html

http://blogs.technet.com/b/security...-security-tools-windows-defender-offline.aspx

 

[shjack26]

Ran Combofix from anti virus (StopSign). It found a couple of folders and deleted those. When I rebooted, an update for Windows defender definitions showed up. Ran the update and Defender is working!. Ran a quick scan and all okay. Running a full scan now. Thanks for your help.