What does "task" mean for a computer?
It's any action carried out by the processor. A program in memory, therefore, is a task. (example: An antivirus program running in memory, which keeps your computer safe)
When Windows has just been started, tasks are already running by default: The desktop (explorer.exe) and the taskbar (systray.exe), two applications which operate separately (this is why you can close the taskbar). When you run a program in Windows, that program becomes a task like all the others. This lets the operating system handle them simultaneously (multitasking) and therefore set priorities.
When tasks are graphical applications (which are shown onscreen) you can easily switch from one to another:
Very often, a task will no longer respond and may "freeze" the computer. When a task has "crashed" (meaning that it is no longer running properly), it generally can't be closed anymore by any of the normal means.
The task manager, which les you handle running processes, must then be used. To make it appear, press <CTRL> <ALT> <DEL> at once.
|If you press <CTRL><ALT> <DEL> again,|
your computer will restart!
Then select the task that is no longer responding (which is often followed by the message "not responding"), click on "End Task," and hope that it ends.
Unfortunately, this system does not work well in Windows, since it isn't clearly defined which places in memory are occupied by which running tasks, to the point where one task crashing brings the others down like dominoes, including explorer.exe.
There is another way to know which tasks are running without temporarily closing off the system, with the help of a little-known program included with Windows: taskman (c:\windows\taskman.exe).