We can protect windows system by creating software restriction policy so virus /spyware or any illegitimate program/application cant be installed.
To manually create Software Restriction Policies you need to do it within the Local Security Policy Editor or Group Policy Editor. If you are a home user you should create these policies using the Local Security Policy editor. If you are on a domain, then your domain administrator should use the Group Policy Editor. To open the Local Security Policy editor, click on the Start button and type Local Security Policy and select the search result that appears. You can open the Group Policy Editor by typing Group Policy instead. In this guide we will use the Local Security Policy Editor in our examples.
Once you open the Local Security Policy Editor, you will see a screen similar to the one below.
