Since this problem is related to the operating system of any computer, this solution works for any other video player which has the same problem on screensavers.
How to disable VLC player's Screensaver for good!
While playing or after played a video on VLC, the Windows screensaver will come on (activate).
The settings option within the VLC won't work to disable it. See the path:
VLC -Tools - Preferences Go to left bottom column at Show settings and activate All button. Navigate down to Video section. Mark the option "Disable screensaver" All that won't disable the screensaver because VLC is related to your Windows settings for screensaver.
Therefore, go to Desktop, right-click, and go to Screensaver options. In Windows Vista is: right-click on Desktop - Personalize - Screen Saver.
Look at "Wait" value. If it says 10 minutes, VLC will activate the screensaver after 10 minutes of idle, EVEN THOUGH your windows screensaver is deactivated. If it say 1 minute, VLC will do it after 1 minute, and so on.
To fix all this problem, is to cheat: change the value to a very high one, like 480 minutes.
Change the value activating the screen saver and deactivating it just like i did before.
From now on, VLC won't bother you at all