>Sorry... I think I mislead you somehow...
>
>my problem is
>
>program A.exe will check for any update for program B.exe, and the same for program B.exe, however, I'm concerned if I call program B.exe from program A.exe, then the program A.exe cannot be replaced, since it is residual in the memory.
>
>How can I run program B.exe from Program A.exe, then release Program A.exe from memory

Aaron,

There is one more way, update old B.exe with new one and run program B.exe from program A.exe as a separate process (RUN /N B.exe), and then exit program A.exe, after that program B.exe can replace program A.exe if necessary.

HTH