I'm using Protection PLUS version 4.1 to manage various types of demos, the purchase of unlock codes, and network usage rights. It's very secure and robust.
As mentioned earlier, I put together a file with DLL32 calls to all of the PLUS dll functions. Since then, I've greatly expanded and improved the ProtPlus.prg that I use to implement all this, and so have made it freely available for download below. Of course, to use this you'd first have to buy the Protection PLUS ver. 4.1 package from Softwarekey.com, and then my stuff will enable you to use it with FWH.
However, if you just download my stuff, it includes a demo exe showing the use of several key PLUS functions so you can see how it works before you decide to buy the main package from Softwarekey.com. My package includes a verbose readme.txt explaining it all. My code also has a lot of explanatory comments included, so it should be reasonably easy to use.
Here's the download...
http://www.leadersoft.com/software/ppp4xhb.zip
- Roger