Hi,
Fews months ago, i needed a licence system. i started witn this thread, it helpd me a lot.
Application Trial Maker[
^]
I ended up with a system totaly diffrent, yet inspierd from the one in the link.
My application is always connected to internet, other wise, the version is demo.
If you need more details (in case your app is also connected to internet) don't hesitate to let me now.
Hope it helps.