Figured out the problem why created users weren't sticking after a reboot or restarting of the service. After installation, the FHFS folder doesn't inherit all the security permissions from the C:\ for some reason. To resolve the issue, I gave the user who installed the program read,write & edit permission to that entire folder. Alternatively, you can make the FHFS inherit all the permissions from the root of C. All the settings should be able to save correctly after that.
As for creating multiple users with the same browser, a simple clearing of the cookies in your browser should do that trick.