Please refer to the following contents
Using the constant defend function for Windows Defender can disable Spyware.
In Vista Windows, please refer to the following contents about how to disable Spyware.
1.Click the Start button.
2.Then select All Programs, and click Windows Defender.
4.Click Options in Tools and Settings.
5.Choose Automatically scan my computer(recommended) in the Automatic scanning
Automatic scanning function is a function of monitoring important Check point in Windows.
The Checkpoint comes out when software’s are installed in PC, Spyware or other junk software’s are automatically installed and the settings of Windows are modified due to some programs.
In Windows Defender，thanks to the automatic scanning function, alarms will be made if there is modification to Checkpoint. Then you can choose whether modification is allowed or not.
Please set modification to allowed continuing to install in the case you would like to install software yourself.