Restartuj kompjuter i udji u safe mod http://serbianforum.org/tutorijali/31450-ulazak-u-safe-mod.html
Izaberi administrator, idi na start, all programs, accessories, system tools , pa system restore.Vrati kompjuter na stanje pre toga.
Ili idi na start, run, kucaj cmd,u cmd-u kucaj net user (ime...