If you have a program that is particularly CPU-intensive and want to make sure it doesn't eat into all of your available processing power, you can use the START command to launch an application at a different level of priority.
The best way to do this is to write a simple batch file like this:
START "<window title>" /<priority> <program>
where <window title> is the name of the window you want to give the program (if it's a console program), and <program> is the name of the executable. You can follow <program> with the usual list of program parameters.
<priority> can be one of several things:
/LOW -- Starts the program in idle priority. The program only runs when nothing else on the system is active.
/BELOWNORMAL -- Stars the program at one step below default priority.
/NORMAL -- Stars the program at default priority.
/ABOVENORMAL - Stars the program at above normal priority (one step above normal)
/HIGH -- Starts the program at high priority (two steps above normal).
/REALTIME - Starts the program in realtime mode.
For example, the file with this statement:
START "Low Priority CMD" /LOW CMD.EXE would start CMD.EXE (the Command Interpreter) with low priority, and the window title "Low Priority CMD." The file with this statement: START /REALTIME GAME.EXE would launch the executeable GAME.EXE in realtime mode.
Note that starting a program in realtime mode is recommended only if you know the program periodically surrenders processing time without being forced to do so. Some applications do not do this; running them in realtime may cause the system to appear to lock up until the program finishes. You may need to experiment under controlled circumstances to find out which programs behave.
Note: It's generally not possible to affect the priority of a system service manually. The priority of a service is set internally. Some services may allow themselves to be run at different levels of priority, but only if the programmer has exposed that functionality.
Serdar Yegulalp is the editor of the Windows 2000 Power Users Newsletter.
This was first published in August 2002