I got something like that it's a trojan virus that's what mine was. It installed this program called "Antivirus XP 08" and it changed my wallpaper to "Spyware found use virus antisoftware" or something like that. Just use a program called "Malwarebytes Anti-malware and run the quick scan and it will get rid of everything.
The 53 000+ zombie kills or whatever it was in Dead Rising. Took me 5 days like 2 hours each day. Really repetitive zombie killing. :P Running over the zombies in the tunnel with the red convertible over and over. :P