KillProcess is an application assassin of the extreme kind. It can terminate almost any process on a Windows machine, including any service and process running in the system. Even protected Microsoft system processes can be terminated. All of this can be done in the matter of milliseconds. The speed that KillProcess can kill your applications with is determined by your computer speed and is not restricted by any other settings within the OS itself. KillProcess is way more powerful than the Task Manager in other terms than speed. It can kill multiple processes, either by multi-select or by clever use of “kill lists”. Using these techniques it is possible to “batch” terminate processes, quickly and swiftly, with a click of a button. KillProcess can also scan the running processes on the computer, and kill them on sight, much like an anti-spyware application would. In KillProcess however you are in charge of which applications should be allowed to run or not – and that applies to the computer as long as you say so. ---- I had issues with some nasty processes recently that even Comodo KillSwitch was unable to kill. Found this software and voila! Killed them in a blink. Just sharing, don't know if it's being mentioned before. http://orangelampsoftware.com/products_killprocess.php
Ask a mod, btw really nice software. Windows 8 is not on the supported list, apparently latest version is Version 2.44 2009-09-02
There are also times when a legitimate Windows process starts hogging memory and you need to kill it, this would make sure its terminated for good.