I am having trouble setting pictures, or pre-set backgrounds to my desktop. The only thing that I am allowed to select is a solid background color. Everything else is "greyed out".  I previouslly had windos xp, and one day it just stopped allowing me to chande the background settinds. i do not know if i unistalled something or what. I have since then downloaded the new windos vista, and still hav the same problem.  What do i need to do to restore the factory setting of being able to change my desktop images.  Does it have something to do with somekind of image sodtware I have damaged?  Any help would be great.