When you open a CMD prompt on a Windows XP system that is installed on a FAT32 partition, and type convert drive: /fs:ntfs, where drive: is the drive letter of the partition on which Windows XP is installed, after the conversion and restart, you receive a message similar to:
Windows could not start because the following file is missing or corrupt: System32\Drivers\Ntfs.sys.
This problem is indicative of the Ntfs.sys file being deleted, or corrupted, during the conversion process.
To fix the problem:
01. Place the Windows XP installation CD in the CD-ROM drive.
02. Restart your computer, booting from the CD-ROM drive.
03. On the Welcome to Setup dialog, press R to repair and press C to start the Recovery Console.
04. Enter the number of the Windows XP instance you wish to log onto and press Enter.
05. Enter the Administrator password when prompted, and press Enter.
06. At the command prompt, type cd \windows\system32\drivers and press Enter.
07. At the command prompt, type ren ntfs.sys ntfs.old and press Enter.
NOTE: It is OK if the ntfs.sys file is not found.
08. At the command prompt, type copy CD-ROM:\i386\ntfs.sys drive:\windows\system32\drivers and press Enter, where CD-ROM: is the drive letter of the CD-ROM drive that contains the Windows XP installation media, and drive: is the drive letter of the partition on which Windows XP is installed.
09. Remove the installation media from the CD-ROM drive.
10. At the command prompt, type quit and press Enter to restart Windows XP normally.