Access denied when copying NTLDR file to hard drive

[needhelp]

I dont know exactly how it happened but last night everything was working fine on my computer but when I booted it up this morning, I got the NTLDR file missing message.
I booted with the windows XP disk and hit the "R" to repair the existing installation when I got to that option and went to the screen where you can put in commands and I typed in "copy D:\i386\ntldrC:\ (D: being my CD ROM drive)
and I got a message saying "Access denied. "
Why was this, I have no password on the computer so that wasnt the problem. I just could not boot up the computer to restore it or anything.
Out of desperation I reinstalled XP over the top but I still lost all my applications and "My documents" folder in the process, needless to say I lost a lot of my files and although my programs were still in the programs folder, they woudnt run.
What I want to know is why I got this message Access denied, I am at a loss to understand why this happened. I thought it would just be a matter of going to the repair screen and typing in the little command as above but no such luck.
Where did I go wrong guys. I have the computer with XP installed and NTFS formatted.
Maybe I should have installed XP in a different folder than the old installation of windows and deleted the old windows when I got the computer running on the new installation.
Please if this happens again, what is my best option to follow. and anyone got any idea why I couldnt get access when I typed in the command line.
Thanks guys

[EzyStvy]

The Ntldr is a protected sytem file.....

After booting off the cd etc...you need to type:

Attrib -h -s C:\ntldr (to remove the protection.

After the copy you need to:
Attrib +h +s C:\ntldr

[glc]

You SHOULD have done a repair reinstall, not a new installation.

[needhelp]

Thanks Ezy have made a note of that. glc, I thought installing xp over the top of the existing installation was more or less a repair installation, whats the difference and how do I do a repair installation. Just want to know for next time. Thanks again guys

[glc]

Procedures are in the Tips and Tricks forum.