China DOS Union

When installing DOS7.10 under XP,
1. Use the DOS7.10 boot disk to enter DOS
2. srcboot c: c:\ntboot_c.dat /s (save the XP boot sector)
3. sys c:
4. srcboot c: c:\bootsect.dos /s (save the DOS boot sector)
5. srcboot c: c:\ntboot_c.dat /r (restore the XP boot sector)
Step 5 gives an error, with the message:
dos7.1 has disabled direct disk access to protect your long filenames. To override
this protection, see the LOCK /? command for more information.
The system has been halted. Press ctrl+alt+del to restart your computer.
----Error:Could not write sector
----Quitting...

Thanks