Add a key code to your applications, you need the Enhancements pack addition to run the code.

the source code has to parts the "Get application registration." code is for getting the HDD identification. and the "Registration conformation" code is for the application you made; place it in the beginning of your code.

                                    ` This code was downloaded from The Game Creators
                                    ` It is reproduced here with full permission
                                    ` http://www.thegamecreators.com
                                    
                                    rem Get application registration.
open to write 1,get computer name$()+".txt"
write string 1,get drive serial$(0)
close file 1
create file block 1,"Computer_ID.zip"
set file block key 1, "4237"
add file to block 1,get computer name$()+".txt"
save file block 1
delete file get computer name$()+".txt"

remstart

rem Registration conformation.
IF GET DRIVE SERIAL$(0)="48E0-79EE"
ELSE
print "-----------------------------------------------------------------"
print "This application is not registered to run on ("+get computer name$()+")!"
print "-----------------------------------------------------------------"
wait key
end
endif

remend