mcclient-vX-XX-X.exe /killclient, unload forcibly MyChat Client from the memory before installation
An installer key. Unload MyChat Client from the memory before installation.
Why do you need it? Imagine you do not use a system for MyChat built-in automatic update and Active Directory integration. You do it in your way. If you install MyChat Client with this key, the installer will unload the process mcclient.exe from the memory before installing the program. The process stops forcibly even during the file transfer. No questions will be asked.
Example
mcclient-v5-21-0.exe /killclient