Can you help me with my laptop problem?

I've searched all over for a solution and can't find one so I've come here to Yahoo! answers to see if anyone might have had the same problem and was able to fix it or maybe if you're just a computer genius. help from anyone is appreciated!
Ok, so I have a Toshiba Laptop running Windows7 Home Premium. its a Satellite L645-S4102 I resently had a virus so I had to restore it to a previous date. After doing that I came back on to my Administrator account and my background was set back to my previous background. I didn't want it so I went to change it. First I tried right clicking a picture on the internet and clicking set as background. a warning popped up saying "Access is Denied." so I thought maybe it was a fluke thing and I tried it on other pictures and it did the same thing. then I saved the picture into my pictures and from there right clicked on it and clicked to set as background and nothing happened. I even right clicked on the desktop and went to personalize and did it that way but still nothing happened. I tried to set it as one of the default backgrounds too but it wouldn't change. its almost like the wallpaper is drawn on there with a permanent marker and can't be washed off. I'm really frustrated bacause I can still change the theme just not the background. so I was wondering if there are any (preferably easy) known solutions to this problem?
All help is welcome and appreciated. Thanks to all in advance!