ok i am talking about software here u perverts..

i am about to give my clients a app that i been working on for so long (done in vb)
has there been successful ways of actually cracking the following..

Each client that i give the app to will provide me with their hard driver serial number. i will take this serial number and compile a unique version of the app based on the serial number provided...
is there a way that anyone knows that this can be cracked or resued by other people with different hard driver serial numbers?
..?