now I can't double click on my desktop icons

I see the icons on my desktop. The background is black. I tried to change the theme and when I click on windows vista as a choice, I can see the color and design in the dialog box. When I click okay, my entire screen goes black and white and I get a message to please wait. Then I can click apply - but my desktop is still black.
Now when I double click on any icons on my screen, nothing happens. I have to go into my start menu to access things. I tried a system restore to about 2 weeks back and there was no positive change.