C# - Method for killing a process/task using PID

Question

I'm trying to create a webservice using C# that will be used to kill a process/task that is currently running. Whenever I try to run it and enter the correct PID to kill that specific task, I get this error message "System.ComponentModel.Win32Exception: 'The system cannot find the file specified'".

public string KillTask(int pid)
    {
        Process killTask = new Process();
        killTask.StartInfo.FileName = (@"C:\Windows\System32\taskkill.exe /f /pid "  + pid);
        killTask.StartInfo.RedirectStandardOutput = true;
        killTask.StartInfo.UseShellExecute = false;
        killTask.Start();
        killTask.WaitForExit();

        return "";
    }

The error message highlights killTask.Start() but I don't quite understand why the system cannot find the file.

Answer 1

If you want to kill the Process(?), you could easily do

var processToKill = Process.GetProcessById(pid);
processToKill.Kill();

Or with a return value (why you want string?)

public bool KillTask(int pid)
{
    try
    {
        var processToKill = Process.GetProcessById(pid);
    }
    catch (ArgumentException) //Exception when no process found
    {
        return false;
    }

    processToKill.Kill();
    return true;
}