Re: desktop background issues
You can setup desktop background just by right clicking on the image and Set as Desktop Background.
If there's no light it means you need to call the vendor OR If a CD/DVD stuck in the drive then get a paper clip and straighten it out then stick into the little hole in the front of the CD/DVD Drive then gently push the clip in until the door opens.
You can use TweakUI as Baba and teggy mentioned.