"why?"

You may have meant to ask more about how to curtail such events, but the simple answer the "why?" is that there are numerous errors in this system. When some software malfunctions, a virus or pest invades the system or even a hardware issue like an overheating CPU can trigger this message.

The message on its own does not lead to a cure, but just opens the door to more questions and let's start with this Tip noted with every new posting:

"If you are asking for help to troubleshoot a computer-related problem, please be sure to include all the necessary information (ie: operating system, model number, hardware, software, etc) that will help others identify your problem for a speedy resolution"

Bob