Every program in Windows has a priority level that determines how much of the system's processing power it receives when more than one program has processes running at the same time. If you're playing a game without running any other programs, changing the priority of the game will have little or no effect. On the other hand, if you also have processes running in the background, boosting the game's priority tells the computer to make sure it plays smoothly, even if it means slowing down other work.
Start your game. You can only change the priority on currently running programs.
Press "Alt-Tab" if necessary to see the Windows taskbar. Right-click the taskbar and click "Task Manager."
Click "More Details" to see the full version of the Task Manager, if you haven't used it before.
Click the top of the "CPU" column to sort by processor activity, causing your game's entry to move near the top of the processes list and making it easier to find.
Right-click the game in the processes list and pick "Go to Details." Task Manager will switch to the Details tab and highlight your game's executable.
Right-click the highlighted file. Mouse over "Set Priority" and then click a new priority. Both "High" and "Above Normal" will give your game priority over almost all other applications, unless you change their priorities as well.
Priority changes only last until you quit a program, so you will have to repeat the process each time you run a game.
Some full-screen games do not allow "Alt-Tab" to work correctly. Running your game in windowed mode or borderless windowed mode avoids this problem.
Never set a game's priority to "Realtime." This causes the computer to forsake all other processes in order to run the game as fast as possible, which can cause other programs -- or even system basics such as the mouse -- to stop working.
Information in this article applies to Windows 8 and 8.1. It may vary slightly or significantly with other versions or operating systems.