Hi! and welcome to the forum...
About your question, it would be great if you can provide more information of your system, and about your "multiple Windows users". But I would assume those users are on the same PC (and not on your LAN) and you run one instance of HFS at time (I mean, not running multiple instances of HFS at the same time).
Well, try this:
1. Press F5 to switch to Expert mode.
2. Then go to Menu > Save options > to file.
3. Move your HFS folder (or where you have HFS.exe) to C:\HFS\
And that should work for all the users on the same PC.
Try that and say us if that worked for you.
Cheers,
Leo.-