window defender

Welcome

If you are using Microsoft Security Essentials, it was turned off by default and should not be turned on. It is not needed, its function was taken over by MSE.

What security sofware are you using?
For virus
Firewall
and malware

tz frantic said:

how can i enable it as it says program is blocked by group policy how
can i unblock it

I had this problem yesterday, It was cause by msa.exe (a malware disguised as an antivirus). You will need to start the Group Policy Editor. Click on administrative Templates and then Windows Components In Windows Components click on Windows Defender disable "Turn off Windows Defender". It worked for me, I hope it does for you.

Good Luck!

P.S: to start the Group Policy Editor, click on start and in the Search Box type group and then click on "Edit Group Policy"

Using the information supplied by the above poster, it may be wise to run an antivirus scan plus the same with malwarebytes.

http://www.malwarebytes.org/mbam.php

Always back up registry before making any changes and you may, also, want to make a system restore point.