I face a problem with Windows XP while loggin in. I have XP pro and created 2 users i) Admin ii) User. My system was ok but now when I switch on my PC it comes to the screen where we can log in as Admin or User but suddenly restarts within 1 second. It happens again again . I have gone through safe Mode and restored but the same thing. Please help me.

First please try to figure out what causes the system restarts? You can view this information by disableing automatic restart on system failures and this option can be obtained by pressing f8 during restarts.