Windows XP / Beginners

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Adjusting Your Application Priorities

Ever since the introduction of the multitasking processor, operating systems have been able to handle running multiple programs at once using the new task switching and segmentation features provided by the CPU. These new technologies are what made it possible for an operating system like the Windows series to be made. Even though PCs nowadays are able to multitask, they really only can do one thing at a time. In order for the operating system to support running hundreds of applications at once, it has to slice up all of the available processing time and give each application a turn.

Operating systems use a variety of techniques to determine which application will get the next available slot to use the CPU. One of the factors that determines this for Windows XP is the priority level at which the application is running.

Every application that runs on your computer has a priority level attached to its runtime record. By default, the operating system starts each application at normal priority, which is right in the middle of the priority spectrum. Applications can run and be assigned six different priority levels ranked highest to lowest: real time, high, above normal, normal, below normal, and low. Because the CPU can only do one thing at a time, the different priority levels allow the operating system to decide which application will get the next CPU burst. If an application is running at high or above normal priority level, it will get more CPU time than an application running at normal.

As you can see, the priority you give an application can impact how fast the program runs.