Take a look at your C: drive, and tell us the name of the folder Windows is in. It's possible someone renamed it when they installed it.
Actually, once you know that, just fix the lines you're trying to run so they read:
expand CD-ROM Drive Letter:\i386\config.nt_ c:\NAME OF WINDOWS DIRECTORY\system32\config.nt
Just replace the NAME OF WINDOWS DIRECTORY with the actual name of the folder on your C drive.
Another method would be to simply extract the file to your root folder, like this:
expand CD-ROM Drive Letter:\i386\config.nt_ c:\
Once you've done that, you can find the file in your c:\ drive, right in the root.
Then, merely copy the file in to your system32 folder inside your windows folder when you find it. Hope this all helps.