I think your problem most likely lies with the windows command start.

Given that you're trying to open an executable file, the start is kinda redundant. You can think of the start command as being the one that windows uses to open the appropriate program for the file type when you double click on any file.

For example, if I pull up a command prompt and manually type in "start F:\cd_key.txt" notepad opens up with cd_key.txt opened up. If I issue this command via the maya system() command, like you, nothing happens and no error is thrown.

Interestingly enough. I can run an executable file with each of these:

system ("f:\install");
system ("start f:\install");
system ("start f:\install.exe");
[ the back-slash \ may also be substited with a forwards slash / ]

The syntax you're using is fine. It's something else that's up.

In the end, it may be the interaction between maya and windows that prevents this from working for you. It may just be this particular file that they don't like.

When it does work, the application is a new task with it's own memory - the memory usage for maya remains unchanged, unlike earlier versions of the command shell used.

Leading me to lean towards it being more a windows issue than one with maya itself.

S.