Write QT code to block an application run on Windows system

  c++, qt, windows

I want to write a program Qt run on Windows.
Example : a program QT name : ManagerTimerApp
When run ManagerTimerApp i set dialog to choose this file
"C:Program Files (x86)GameFastGame.exe"
FastGame will cannot run.
So i don’t know api function Qt to block FastGame.
Could you please help me?
Thank you!

Source: Windows Questions