Fix the installer
I had several isues installing Faxmaker which could have been easily prevented if your installer would work properly.
I could install the software without problems and got an success message, but it was impossible to configure.
The points your installer should check bevore starting to install are the following:
Check if Windows is blocking the exe. It will install anyway but does not work afterwards.
Check if the user has the rights needed. Again it will install anyway but does not work
And please give errormessages related to the errors.
I got only Your Kex is invalid and searched only in this direction. But the problem was only insufficient rights and security features of MS.