How will you remove this error “ ntldr missing press any key to reboot the system” ?

Reboot the system with XP, ( apply also on server2003,) cd
On setup screen press to R to repair the window
Now provide the administrator password
C:\>cd f:( your cd drive latter, f is taken as the example )
f:\>cd i386
f:\>copy ntldr c:\
f:\>exit
reboot the system