Windows Defender is an application that has functions similar to an antivirus program. It adds itself automatically when installing operating systems such as Windows Vista or Windows 7 and protects the computer against spyware and other types of computer viruses. If you want to disable Windows Defender on your computer, you can do so by using the "Local Group Policy Editor."
Open the "Local Group Policy Editor." Click "Start," type "Edit Group Policy" and press "Enter."
Expand the group policy folders labeled "Computer Configuration," "Administrative Templates," "Windows Components," and "Windows Defender" on the left navigation pane. Double-click the group policy folders to expand them.
Click "Turn off Windows Defender" on the right of the window, then click "Edit Policy Setting" to open the "Turn off Windows Defender" dialog box.
Click the circle next to "Enabled" to disable Windows Defender.
Click "Apply" to save the settings and click "OK" to close the "Turn off Windows Defender" dialog box.