By best I mean more time tested, easier to implement and easier for the users to work with. I do not want my licensing crap to interfere with their work.
I was thinking of launching a WCF service that check with my license DB if it’s a valid license and if it is, send a True.
If the returned response is False, then shut down the program after telling them to fix their license.
Do you think this is a good way to handle it?
You will need to develop or find an algorithm that creates sufficiently complex strings for your license keys.
Generate the license key based on some bit of information unique to a user, like their E-Mail address.
Your program would then require the user to enter their E-Mail address and license key. It would then ensure the license key is correct by running the same algorithm you did to generate it in the first place.