Depends on how you will be handing license key generation.
For instance, Handango.com can generate keys for you based on a formula you
give them. It is not based on a ID of the device but on the username that is
stored in the device. If you went this route then it is pretty easy to just
create a DLL yourself (non managed so people cannot see how to generate a
key themselves) and then just call it to verify the key value.
I would not really purchase a 3rd party solution until you take a look at
creating something yourself AND determining who will be generating all your
license keys (you want to make sure that any 3rd party solution can
generate/verify keys the same way as your key generator.)
All in all it is pretty simple unless you want to try (keyword here) to make
it hack proof..
Some simple rules to follow:
1. Make it hard enough to hack so that purchasing a key is cheaper then the
time spend hacking.
2. Dont try to make it so an Egg-Head cannot hack it because you wont be
able to. Concentrate on keeping the other 90% of the people out there from
hacking it instead and spend the rest of your time creating another product.
Hope this helps!
