Having A Serial Key Activate The Compiled .EXE

[MadQuestion]

I was wondering if there was any way in that I could script a .exe file so that it checks a entered serial key against a list of variables and if the entered key code and the variable match could the script delete the variable from the database/list. I would like to be able to offer subscription based use for 30 days of my scripts but I dont want the serial codes to just be reused again once purchased and entered..

[Marcus Tettmar]

Yes you can check a value against a database and yes you can delete a value from a database. But if these .exe files are distributed throughout "the wild" how do they have access to the database?

I have a feeling what you're really asking for are ideas on how you might create some kind of license checking system.

I'd suggest your database is on a web server. Have your .exe do a HTTPRequest to POST the license key to a resource on the server. This could be .e.g. a PHP script or similar. That PHP checks the "license key" against your database. And sends something back.
First it makes sure it is "valid" . I.e. one that you provided and actually exists. If not, it sends a code back which tells the .exe not to run. If you only want it to be valid for 30 days then I guess you have it store the date it was first "seen". If the current date is less than 30 days after that date, send something back to tell the macro to run, otherwise tell it it's expired and not to run.