When I try to change the background on my computer nothing happens. Anyone know how to fix it?

Question

My sister made a big mistake and had me download this 08 XP Antivirus thinking it was good but ended up almost killing my computer. After it was gone and everything was back to normal, I turned on my computer and it was a blue with a notice right in the middle. Restarted my computer and the notice was gone but when i tried to change the background the properties thing only has three tabs and none of them have anything to do with the desktop. What do I do to get rid of it and change my background???????

Answer 1

95% sure your registry and/or system config files (system32) is corrupt...the virus most likely left a command in ur registry that configures appearance and fonts....