Unable to start computer in a normal mode

I was unable to start my Windows XP computer. When I was booting it I got messed up with an error. After restoring my computer to an earlier date, the screen went dark. The only way I can start it up is through Safe mode with networking. It did not help when I used the Last known good configuration option. I successfully started it using Safe mode, it showed that the computer has been restored to the specific date. I shut down and restarted the computer but it still gave me the same error. Why is this so? I need help. Thanks!
