We have some XP machines that can not boot up normally. When boot up, we cannot see windows log in screen, just only blue background and white mouse cursor, we can move mouse cursor only. I have already tried to boot windows in safemode and restore last known condition with no luck. Even when I try to repair windows by XP OS install CD, the setup process is still stuck at same status on first reboot, only background and mouse cursor. I don't know it may cause by a virus or not. Could anyone help me on this issue, it happens on some computers, not only one.