Windows AntiSpyware is now known as Windows Defender

Windows Anti-Spyware(beta) is a security technology that helps protect Windows users from spyware and other potentially unwanted software. Known spyware on your PC can be detected and removed. This helps reduce negative effects caused by spyware, including slow PC performance, annoying pop-up ads, unwanted changes to Internet settings, and unauthorized use of your private information. Continuous protection improves Internet browsing safety by blocking more than 50 ways spyware can enter your PC.

To anyone experiencing the "Error 1609. An error occurred while applying security settings..." solution follows :

1. Go to your computeradministration
2. Go to User administration
3. Select "groups"
4. Right click and select "New group"
5. Call the group "Users"
6. Press create

It should install correctly now