Migrate HDD under Win2k

See my answer to your second question.

Note: for setting up the large hard drive as a data storage drive, it works "best" if both hard drives are from the same manufacture.

A question?
How similar or different are the 2 PCs?

If the hardware is basically identical, Windows may not have a problem with swapping the hard drives.
By identical, I mean:

Same chip-set on the motherboard.
(This includes identical IDE controllers.)

Similar video cards.

If the hardware is very different:

Pentium 3 versus Pentium 4;
Pentium versus Athlon;

You will need to do the backup, clean install, and restore procedure.

Chas

I have been lucky on a couple of occasions plugging the HDD into the second, and quite different, machine and firing it up. Windows 2K bleated about it and gave me a blue error screen, but using the installation CD and doing a repair installation of the Operating System brought it back up.

After doing that, you still have to go down the path of installing all updates, because the repair installation takes the system back to the level that is on the CD, but it is worth a go.

However, I have to say that BEFORE you do any of this, do as Chas says and back up all your data, email messages, address book, favourites, email account settings, and anything else that you can think of, then have a go. If it works - fine. If it doesn't - it is a clean install, as Chas says.