If I were you

1) in safe mode->right click computer->properties->advance->
startup & recovery-> setting-> uncheck auto restart.
2)restart the system and check the error message.
3)in safe mode->right click computer-> properties-> hard ware -> device manager-> check any question mark or exclamation mark.
4)start a clean start up. (seach in Microsoft keyword clean start up)
5)last resort, start xp boot disk, into recovery console and do a chkdsk.

Hope can help, good luck...