The known and proven way to do that: a hardware USB-dongle.
If you want to do it in software let them tell you the MAC-address of their PC or their Windows license code and check that hardcoded or put it encrypted in a parameter file you send them.
Kees
Ok sup people. i was wondering how i send a program and lock it on their computer because i dont want the program all over how would i be able to do that . thanks & please.

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