You might start Win2k on your 'linux-pc' by using a startdiskette. You can make such a diskette on your second PC.

Sometimes the start diskette won't work. Check it by starting your second PC with it.
If it doesn't work, then there are some files missing; you may copy the missing files manually from the C:\ map. It must contain (check in explorer with hidden files shown):
autoexec.nt
boot.ini
config.nt
ntdetect.com
ntldr
setup.log

There's a good change that you can start Win2k on your 'linux-pc' with it.
Then there is a change that Win2k sees the problem (with the boot loader or the MBR) while starting and fixes it.
Or you might force it by a check disk. Win2k needs to restart for that, so keep your start diskette in the PC.

No guarantee but without a Win2k CD you cannot even reinstall (as other member suggested )

(Starting from a Win2k CD you have the possibility to fix the former installation.)