Windows OS .... troubles and can't access my cad files

Sorry if this is a little off topic but figured someone would know out
of this group as I've become to trust what a lot of you know and help
with.

I've got a windows 2000 message upon start up that says:

Windows 2000 could not start because the following file is missing or
corrupt: <windows><system32\ntoskrnl.exe.
Please reinstall a copy of the above file

I've got a spare comp (identical computers) that I've gotten the file
from and onto a CD (1.6 mb or so) but how do I get it on my comp
that's down? I'll call whoever is able to help.... providing a
number....

I SINCERELY APOLOGIZE for this being a bit off topic but can't get CAD
files I've been working on this comp... I don't want to lose this by
reinstalling from boot cd's ( or can I restore OS w/o losing my files?)
Darren Lucke
701-720-3688