You can create a personalized screen saver in Windows 7, by displaying selected pictures as a slide show when you aren’t actively using your computer. To do this, follow the simple steps below:
1. Open Screen Saver Settings by going to Control Panel\Appearance and Personalization\Personalization.
2. Under Screen saver, chose Photos from the list.
3. To change screen saver settings, click Settings to do following:
- To specify the photos to use for your screen saver, click Browse, choose the folder that contains the pictures, and then click OK.
- To change the speed which the photos change in the slide show.
- To make pictures appear in a random order, select the Shuffle pictures check box.
4. Click Save to save the setting. Click OK.
Now your screensaver is ready to use 
