powered up computer. All looked good until the boot stopped showing only wallpaper. This is my sons computer and I understand there is no backup or restore disk. I was able to make a boot cd for diagnostics, and have been doing lots of research all the way to the cmd prompt. x:\ If I look at the setup when booting it shows no hard drive but if I select f12 for bootselection it shows hard drive. I suspect a virus effecting the boot sector.