This is not a tweak, but a great little feature in Windows! For a great way to put your digital photos to work, try creating a slide show presentation for use as a screen saver.
1. On your desktop, Right-click in the empty space and then click Properties option.
2. In the Window, Click the Screen Saver tab.
3. Screensaver Tab shows the Screensaver list, in the list click My Pictures Slideshow.
4. Click Settings to make any image adjustments, such as Set the time to change picture and you can change the size of the picture .you can use transition effects between pictures, and then click OK.
5. Click the >Preview button to see your own screensaver.
Now your screen saver is a random display of the pictures taken from your My Pictures folder.
This is same procedure like you do in the in Windows XP, But In Vista and windows 7 the user Interface design is changed.
1. on your desktop, Right-click in the empty space and then click Personalize option.
2. Click the Screen Saver tab in the Right side bottom of the corner.
3. In the Screen saver list, click Photos.
4. Click Settings to Browse Pictures folder and to make any adjustments, such as pictures Speed fast, slow and you can shuffle the pictures and then click OK.
5. Click the Preview button to see your own screensaver.