This is going to be a simple and strait forward example on finding and killing a process using windows powershell. For the example we are going to start and kill the cmd process.
This is a example to find cmd (command prompt)
tasklist | findstr cmd

Use the selected id to kill the process
Stop-Process -id 12256

you can stop a process by name:
Stop-Process -name CMD
Stop-Process -name CMD
Nice ???? thank you