When running programs in Windows, sometimes a particular application won’t respond in a timely fashion. If the application doesn’t respond when you type a key, that could be a problem and may lead to the dreaded “not responding” error message.  Similarly, if the program doesn’t acknowledge when you click on the Close Program “X”, it may be because the application is running processes in the background which are using too many resources and slowing down the overall speed of your PC.

Plausible reasons for this result exist. For instance, a long, computer intensive computation may result in your program responding slowly. A program performing a complicated action on a large image would be a good example. Attempting to exit the window may result in a few seconds of nothingness and then a “Not Responding” display on the title bar. This message indicates that the request has been sent, but is not being received for some reason.

The most likely reason a program does not respond is due to corrupt applications, an overload of resources or a problem with how Windows is responding to the application that is waiting.  It is easiest to deal with corrupt applications.  Reinstalling the application is usually the best way to solve this problem.  The other two problems are harder to solve, depending on your approach.

Here are a few likely causes of the “Not Responding” error message:

Programming Error -  Infinite loops are a common error where algorithms are written to never end.  The program becomes unresponsive and Windows becomes unable to operate.  If you notice an action caused an infinite loop, avoid the action in the future.

Software Design Error - this is just another form of what was already discussed, but I classify it as a different type of problem.  Occasionally, for example, an error message will pop-up while a program is running.  Sometimes the pop-up error message will cause the main window to stop working until the “OK” button is clicked.  If the box does not appear where it is suppose to, such as popping-up behind the main window or off the screen, then the application gets hung up until you click on the “OK” button in a message box that you can’t even see.

Hardware - In some cases, when hardware is malfunctioning, it can cause the software that interacts with it to fail in ways that make it unresponsive. As a consequence the next program to attempt to read from the hardware device might be end up “Not Responding” because of previous problem, for example, when trying to read from a faulty USB memory stick.

Hardware Drivers - Here is a synopsis of prior ideas.  No matter how good the hardware on your computer is, the system can freeze or hang if the operating software is flawed.  If you encounter a hung system frequently when you use a given device, you may want to first be sure that you have installed the latest drivers for that device.  Of course, you should also be sure you have installed the latest Windows software updates.

Viruses and Spyware - either because they are poorly written or because it is an intentional act, viruses and spyware can disrupt other programs or Windows and then they might become unresponsive.  You need to be certain that your anti-virus and your anti-spyware software is both functioning and current.