Opening the power management of the computer can be completed through the following steps:

Open the Control Panel of the Windows operating system, which can be searched in the Start menu or accessed through icons on the computer desktop.

In the Control Panel window, locate and select the 'Hardware and Sound' option.

In the "Hardware and Sound" window, click on "Power Options".

After entering "Power Options", you can see the current power management settings of the computer. Settings can be made as needed, such as selecting sleep mode, screen shutdown time, power button behavior, etc.

If you need more advanced settings, you can go to the "Change Plan Settings" or "Change Advanced Power Settings" tab to make adjustments.

After setting up, click the "Save Changes" button to save the new power management settings.

In addition, some computer manufacturers also provide specialized power management tools or software, such as Dell's Power Manager and Lenovo's ThinkPad Power Manager. These tools usually have richer functions and more detailed power management settings, which can be installed and used according to their own needs.