Fix Windows XP Without Re-Installation

below there are ways to fix your windows xp in your computer
Repair Install
If your Windows XP is corrupted and You do not have another operating system to boot. You can do Repair Install then :

Make sure you have valid Windows XP the key
The entire process will take less than 1 / 2 or 1 hour, depending on your computer specifications.
If you asked for an administrator password, you should choose second Repair option, not the first
Insert your Windows XP CD and do the boot from the CD.
When it appeared the second repair option R = Repair, press the R key
This will start the repair.
Press the F8 key to agree the next process "I Agree at the Licensing Agreement".
Press R when the directory where you installed Windows XP. Usually C: \ WINDOWS next will be checked drive C: and start copying files. And automatically restart if necessary. Let your CD in the drive.
Next you will see a picture of "progress bar" that is part of the repair.