Difference between taskkill and taskkill /f

Question

On Microsoft Technet I can read that taskkill has a /f parameter to kill a process forcefully. I wonder what this does internally, to understand the impact of such an action.

taskkill (without /f) does not simply send a WM_CLOSE message to the process, otherwise my application would ask whether or not to save the open documents. This makes me assume that it already operates on a TerminateProcess (MSDN) level. However, TerminateProcess does not have a parameter for forcing a kill.

So, what do taskkill and taskkill /f do internally?

I read the related question Difference between C# Process.Kill() and Taskkill but it does not have an answer.

Answer 1

Most likely taskkill /f uses TerminateProcess, where as taskkill without /f just posts a WM_QUIT message (not WM_CLOSE). The docs says that TerminateProcess unconditionally kills the process.

You can try following experiments:

1. Launch notepad.exe and type a few chars in the notpad window
2. Type taskkill /f /im notepad.exe. Notepad will quit immediately

Now do this:

1. Launch notepad.exe and type a few chars in the notpad window
2. Type taskkill /im notepad.exe. Notepad won't quit immediately but it will quit ask if you want to save modifiactions.