C# Process Killing

Killing processes by their name can be easily done in C# (as the other answers already showed perfectly). If you however want to kill processes based on the full path of the executable things get more tricky. One way to do that would be to use WMI, another way would be to use the Module32First Windows API function.

The sample below uses the latter approach. It first selects a subset of the running processes by their name and then queries each of these processes for their full executable path. Note that this path will be the actual path of the image being executed, which is not necessarily the executable that was launched (e.g. on x64 systems the actual path to calc.exe will be C:\Windows\SysWOW64\calc.exe even if the file C:\Windows\system32\calc.exe was started). All processes with a matching path are returned by GetProcessesByPath:

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Runtime.ConstrainedExecution;
using System.Runtime.InteropServices;
using Microsoft.Win32.SafeHandles;

class Program
{
    static void Main(string[] args)
    {
        Process[] processList = GetProcessesByPath(@"C:\Program Files\MyCalculator\calc.exe");
        foreach (var process in processList)
        {
            if (!process.HasExited)
                process.Kill();
        }
    }

    static Process[] GetProcessesByPath(string path)
    {
        List<Process> result = new List<Process>();

        string processName = Path.GetFileNameWithoutExtension(path);
        foreach (var process in Process.GetProcessesByName(processName))
        {
            ToolHelpHandle hModuleSnap = NativeMethods.CreateToolhelp32Snapshot(NativeMethods.SnapshotFlags.Module, (uint)process.Id);
            if (!hModuleSnap.IsInvalid)
            {
                NativeMethods.MODULEENTRY32 me32 = new NativeMethods.MODULEENTRY32();
                me32.dwSize = (uint)System.Runtim