Am I right in thinking you mean NTLDR and not NLDTR? If so here is the fix.
To fix the error on startup of NTLDR is missing in Win XP you should follow the steps below using a full version Win XP CD and the Recovery Console.
Insert the Windows CD and start the computer making sure the computer boots to the CD first.
When the Welcome to Setup
screen appears, press R. (this may take a while to load)
Type a number corresponding to the Windows installation you wish to repair (usually 1) and press Enter. When prompted, type the administrator password and press Enter. (if no password was entered on you system then just press enter)
From the command prompt you want to copy NTLDR and NTDETECT.COM from the i386 folder of the CD to the root folder of the hard drive. This is much easier than it sounds and can be done by typing the commands below.
In the examples below C: is presumed to be your hard drive and D: is presumed to be your CD drive. You will need to change the drive letters to your own if you have more than one drive. ( if you are having problems entering \ then try pressing the # key to see if that works)
Type these 2 commands exactly and press enter after each one.
COPY D:\I386\NTLDR C:\
COPY D:\I386\NTDETECT.COM C:\
Now remove the Windows XP CD from the drive and restart the computer and your computer should now start normally.