Microsoft Security Essentials does not turn on at startup

Of late, MSE has stopped starting the real time protection on its own. I see the red icon in the tray.
I tried to start the real time protection myself but I get an error code: 0x800705b4.

I had a look at a similar problem here and I find that Microsoft AntiVirus Service is started even when the icon is red. I have even repaired my .NET from Control Panel. None of it seems to help.

A strange thing is that task manager's Services tab shows MSE as running. I decided to run a scan and then the icon updated to show Potentially Unprotected which is normal because I use CCleaner.

Can someone please tell me how to solve this?

To be sure, I would load MSCONFIG (START > RUN > MSCONFIG> OK) and check the Start Up tab.

You'll be able to see whats starting, and amend the things that you don't want on boot.

Check the ones you want, uncheck the ones that you don't. CCleaner (Piriform.com) also has a StartUp manager, which you might also like to check out.

In my experience, there's always a toolbar or some other unwanted thing there that runs before MSE and kills it.

Best / Crit

The error 0x800705b4 shows up if you have have disabled the Defender in the registry:

• Press Win Key + R combination, type regedit.exe in Run dialog box and hit Enter to open the Registry Editor.

• Navigate to the following location:

  HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender

• change the value DisableAntiSpyware from 1 to 0.

Reboot and now Defender should work fine.

OS Win7 64 bit The "DisableAntiSpyware" Registry location was as follows: HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows Defender , double clicked "DisableAntiSpyware", changed value from "1" to "0" now "real-time protection" working.

On the Registry editor file menu, entered Edit then Find then entered "DisableAntiSpyware" without quotes to find.