Lots of people I spoke to had problems with windows XP not booting up completely. Loading gets stuck at the Windows XP loadign screen with the black background and green bars moving from left to right. In this case, the boot sector of the OS has already been damaged or corrupted.
Now, unlike windows Vista or Windows 7 that has a STARTUP REPAIR option. The only thing we can do for XP is run FIXBOOT in the recovery console.
"The fixboot command is a Recovery Console command that writes a new partition boot sector to the system partition that you specify."
Just type FIXBOOT C: at the command prompt of the recovery console, then press ENTER on your keyboard. This will write a new BOOT SECTOR and after the process is done, just type EXIT then press ENTER on the keyboard.
The computer will restart and you should be able to boot to windows normally.