Hi
How far does it get/what error message do you get? i.e. do you get a blue screen during boot (possible mismatched hardware) or do you not even get as far as the boot menu?
You could try booting from a floppy.
With the HD plugged into the working PC, format a floppy disk under NT, copy the following files from the root of your drive - ntldr, ntdetect.com and boot.ini, then put the drive in your other PC, put the floppy in, and try to boot. If you cnt see these files, enable the display of hidden files in tools > options
The way to recover an NT installation is to make boot disks, and once booted with these, select the repair option. Obviously, using this option may render the drive unusable in the other machine
You need 3 blank floppy disks
Make the disks by executing winnt.exe from a command prompt with the switch /ox
Winnt.exe can be found on your original installation media
Run the command from a command prompt;
1. start > run > cmd [enter]
2. [path to media]\i386\winnt.exe /ox
I hope this helps, but if not, please reply here