For my projects, I love to use, NSIS installer. Sometimes, usually for plug-ins, I need to check if host program runs, then I try to close, terminate or kill it. Here is a simple plug-in help terminate, close, quit and detect any working process from NSIS installer.
Notes for usage:

Download NSIS Installer
NSIS Installer
Download Kill Process for NSIS
Unrar it [...]