>>>If programmed and called properly, the external application should not stay in the memore after it finishes. How the event monitor runs external applications?
>>
>>External program executed using:
>>Do someexternalprogram.exe
>>
>>The actual code reads the command line from a table and executes the line using macro substitution.
>
>You're executing it as VFP APP (internal, in the context of the calling application) not EXE (external). You don't need to build EXE in this case. APP will work the same.
>VFP caches everything that's why it still in use after it finishes. You can try CLEAR PROGRAM but I'm not sure if it'll help.

CLEAR PROGRAM worked. Thanks Sergey!