Its only started happenning, but when my desktop for no reason went to black, I reinstated a picture using personalization tab in 'display'. I run windows 7 ultimate. But after about 30 minutes it reverts back to black again!
The screen saver kicks in as normal.
How do I get the desktop back to my picture permanently?
Go to personalize again
Click on Desktop background at the bottom
If you have more than 1 picture ticked, it will default to changing every 30 minutes. Untick all the pictures except the one that you actually want (You can only see the checkboxes if you hover over or click picture. If there are lots of pictures, you can untick them all by clicking in a clear area, then just tick the one that you one is ticked then the "Change picture every" option is greyed out.