Windows 7: How to disable Windows defender?

Ok, just uninstalled Microsoft security essentials and installed F-secure.

Now windows defender is active again. How i can disable it?

See if this helps:

Windows Defender - Turn On or Off

Click start, type Windows Defender in the search box.
Click on Windows Defender in the upper panel.
When Windows Defender opens, select Options.
From the Options menu, select Administrator.
In the box on the right, uncheck 'Use this Program'.
Save and Exit.

You can also disable it in 'Services'

Services - Start or Disable

Worked.

Topic solved.