Remove Key Code Install Requirement from Software

I have a custom made program for my business that has the need to provide a key code to install based on the computer's unique id. The software coder up and left me with the software that work fine on one PC but he never gave me the keygen to make it useful on my other computers. I just need that piece of code removed or altered so i can install it on my other business computers. According to the description he gave me it was written i "unmanaged C++," so I hope that helps some for you to place your bids/ideas. I do not have the source code, I just have the .exe files and .dll files to run the software. So i guess what I really need is for it to be cracked or opened somehow. I can give you my current PC id # and the code it spit out for it to work on there but that is as much as I have. I think my coder ran off with the money, files and all. Let me know if you can help. Will pay as soon as a solution is reached. Thanks!