Screensaver Lockscreen using GPEdit

You will need to be an administrator on the local machine or in AD to make these changes.

Open GPEDIT.msc

Under “User Configuration” go to Administrative Templates -> Control Panel -> Personalization

Edit and enable the Following Settings

1. Enable Screen Saver -> Enable
2. Prevent Changing Screen Saver -> Enable
3. Password Protect the Screen Saver -> Enable
4. Screen Saver Timeout -> Enable and Set to 300 Seconds
5. Force Specific Screen Saver ->  Enable and set to %Systemroot%\System32\Mystify.scr
   
   

Apply and hit ok.

Open up the cmd prompt and type in gpupdate \force and logout when asked.