To restore a missing or corrupt ntfs.sys file you must have the Windows XP CD and follow the below steps.

1. Insert the Windows XP CD into the computer and restart the computer.
2. As the computer is starting make sure to press a key to boot from the CD.
3. In the Windows XP setup screen press the 'R' key to run the Windows Recovery Console.
4. If prompted enter the number of Windows installation you're repairing.
5. At the command prompt type the below command.

copy x:\i386\ntfs.sys c:\windows\system32\drivers

* In the above example you would replace x: with the letter of your CD-ROM drive. Many computers have the CD-ROM drive configured as the D: drive.

6. If ntfs.sys is still on the computer you'll be prompted if you wish to overwrite the file. If prompted, press the Y key for Yes to overwrite the file.
7. Once the file has been successfully copied remove the CD and reboot your computer.