Kieth, the license for Mach is a small file called Mach1Lic.dat and is 201 K in size
You copy this file and put it into C:\Mach3 and that's it, If it wants to overwrite an existing file then let it.

When you open up Mach3 if you go to Help on the top menu bar then About Mach3 controller it should give your man in the top box proving it is licensed.

If for some reason it hasn't taken the file it will say demo version.

John S.