well i can tell you are an apple user, judging by the lingo
what kind of pc/laptop do you have?
also, try ending the PROCESS not the TASK. so lets say you open up task manager (ctrl - alt - del) and you see something says "not responding". instead of clicking "end task", right click it and say "go to process". once you are there, simply click end process
be carefull, however, because if it is something like explorer.exe, it could crash your system (that is the main process of windows, you could say)