My other computer boots up to a pattern of brightly colored squares and rectangles. This red, blue yellow and green patern blocks access to everyhing. It may be a wallpaper and all shortcuts and task bar are missing. The mouse cursor is active but there is nohing to click on. The Task Manager has been disabled and safe mode boots to a black screen with nohing else visible. Is there a way to recover from this attack?
It's difficult to advise you without knowing the operating system and service pack but would assume that it's either XP, SP3 hopefully, or Vista, SP1 hopefully, so have you tried booting into Safe Mode by tapping F8 continuously while booting up and then using System Restore to go back to before this happened?
Or choose "Last Known Good Configuration".
This could also be a faulty or corrupted Video driver.