Follow the simple steps :
Step 1 : Create a simple folder in your “my Pictures” or put it anywhere for that matter, you don’t have to name it anything special, copy all the pictures you wish to have for your screensaver into that folder.
Step 2: Right-click on the desktop, and then click Properties.

Step 3 : In the Display Properties dialog box, click the Screen Saver tab. Then, click the Screen saver list, and click My Pictures Slideshow.

Step 4 : Click OK. Thats it , Now when will screensaver appear on your desktop , it will show the pictures from the “My Picture” folder.
Note : To stop the screensaver, simply go into properties (on desktop right - click and go to properties) In the screensaver tab you can choose another screensaver or simply select “none” to disable any screensaver.