Software that runs on only 1 computer

I have a program I purchased a while ago that requires a .REG file created for me based on the Hardware ID of the computer I had at the time.

Since I changed boxes and the hardware ID has changed, I can't run the program (can't contact the software author)

They had sent me a small utility file that read the ID of my box and when I sent it back to them, the sent me a reg file based on that ID. I believe it was created using some kind of hex code generator.

Does anyone know of a way around this or perhaps a way to fool the reg file.

Is there any way to change the current hardware ID of a machine?

Thanks!