Ok, try turning off your computer by pulling the plug out in the back, if you are running xp, when you turn it back on you will have forced it to give you the safe mode option, operating in safe mode takes away some stuff, but if you go into safe mode and still cannot access the desktop properties, then we will know whether or not you have a serious problem or a minor one. Try this and then post an update and I will try to help as best I can
