An application or software not responding to your commands is nothing rare, and that is very much seen in the Windows OS where your currently running software would stop responding, and only the OS would give a popup window saying what's going on. The problem is very common, but the solution many of us always know is by opening the Task Manager and force closing the software, or initially wait until you are convinced that the software isn't going to respond.
Program not responding - First Workaround
The first workaround would always be to rectify the actual problem, than to look for a solution to move ahead. One of the reasons for the software to not respond properly is the load it takes. Either the internal hardware of the computer isn't able to take up the load, or there is something within the software which is making it unstable. You cannot do much about the latter because the software isn't responding so you won't be able to access it, and for the former, try to shut down the other running applications and see if things are getting better. Seriously these are not the workarounds which would always become the final solution, but why not try them to understand the root cause?
Program not terminating even from Task Manager? Here's the workaround
It's more than just frustration when the app is not responding, and you are unable to kill it through the Task Manager.
You have tried closing the app by clicking on "Close the Program" in the warning popup, that didn't work. Then tried closing it by going to the Task Manager, selecting the app and clicking "End Task", but if the app still stays there, unresponsive, then you need to dig into it deeper, and that cannot be done directly through the Task Manager and there needs to be a tool which reaches the process level ID and then kills it from there, which is possible with a tool named "Process Explorer". It is a free tool, and it works fine with Windows 7 (tested on Home, Ultimate versions) and Windows 8 OS.
Download the Process Explorer zip, unzip it and open the executable file as an administrator and you will be shown the big list of all the applications, system processes running in the computer.
Navigate to the exact app / software which is causing the problem and is not responding even when you are trying to force close it.
Right click on the application. The list of options for that particular application would show "Kill Process Tree". Click on that to force kill the unresponsive app. The other options in the list aren't of any help for the current solution.
You would be shown a warning whether you wanted to kill the executable file and its descendants. Confirm it, and you are done. All the headache of trying to close it in your own ways ends with this simple utility, which is good to keep not just for killing tasks but also for every other thing you used to do through the Windows Task Manager.
Download Process Explorer: Click here
Here is a little explanation on what Process Explorer is.
The Process Explorer doesn't show you the main application but shows the information about the handles and DLLs processes which are opened or loaded, and there are two modes in which the Explorer runs: Handle mode and DLL mode, where the handle mode would show the handles that the process selected in the current window has opened, while the DLL mode has the DLLs and memory-mapped files which the process has loaded. Such a deep access is what makes the Process Explorer close even the apps which do not respond.
Second Workaround: Use Unlocker Tool
If the Process Explorer is a harder (although very useful) one for you to understand and use to kill a process, the best alternative would be to use a tool called Unlocker, which does it in an easier way, although it won't show you how and what it does. Download the Unlocker tool and install it. Then, start the software from the Start menu and open the particular folder where the file is located.
Select the executable file which is causing the problem, and then select "Kill Process", and you are done.
Download Unlocker: Click here
* These two guides are helpful when you are stuck with some important stuff running around, and you didn't want to restart the computer at that particular point of time. If you are able to, then restart the computer and most of the problem usually gets solved, but doing that always won't be a wiser option than using either the Process Explorer or the Unlocker tools.