I don't know if this helps you, but the software installation is tied to the volume serial number (vsn) of the hard disk. If you still have your old activation code, you can run it on a new machine by changing the vsn of your new hard disk to be the same as the old one using a routine like this one:-
formatting link
Install it in your system32 directory and run it. (volumeid)
I haven't tried it so don't know if it works.
You must know your old activation code and you must know your old hard disk vsn. To find your current vsn open a dos window and run the command line vol c:. the vsn will be in the format ****-****
I have not heard of any problems with changing the vsn of the hard disk (it changes randomly anyway whenever you do a low-level format).
Of course this also means it is possible to port the software to as many computers as you like with only one activation code, just by changing the vsn of each pc hard disk. Obviously if in doing so you contravene the licence agreement this could be software piracy. I do not condone software piracy. I'm not familiar with the licence agreement and would encourage anybody contemplating this to check the agreement to ensure you do not break the law if this is indeed illegal.
Hope this helps.
Dave