Fix: Sleep Mode is not working in Windows 8.1
Every once in a while it happens to every user, you put your Windows system into sleep and it doesn’t want to come alive anymore. Luckily there are only a few possible errors we need to take care of in order to find the answer. About 90% of all Sleep and Hibernate problems are due to wrong settings in the Power Options. But first we need to know what the different is between sleep and hibernation.
The difference between sleep mode and hibernate (and hybride sleep)
Sleep is a power-saving state that allows a computer to quickly resume to full-power operation (which would normally be within several seconds) when you want to start working again. Sleep is like putting your MP3 player on pause. The player immediately stops doing all that he is doing, thereby saving some energy and in seconds it ready to restart at your request. If you want to know how to enable the hibernate mode, just take a look at this article.
Hibernating on the other hand is what your laptop does when you close the lid. While sleep puts all your work in the memory and keeps using some power for all the other functions to continue to work, hibernation saves your everything you are doing unto your hard disk, including your open documents and programs and then turns of your computer.
Hybrid sleep is designed primarily for desktop computers. Hybrid sleep is a combination of sleep and hibernate—it puts any open documents and programs in memory and on your hard disk, and then puts your computer into a low-power state so that you can quickly resume your work. That way, if a power failure occurs, Windows can restore your work from your hard disk. When hybrid sleep is turned on, putting your computer into sleep automatically puts your computer into hybrid sleep. Hybrid sleep is typically turned on by default on desktop computers. [Microsoft]
How to fix the sleep mode
Most of the times, we can blame a hardware device for keeping your computer awake. USB flash drives and USB mice are among the most common devices that can keep your computer awake. Always make sure that you have the most current drivers all of your devices.
To prevent a device from waking your computer
Open the Device Manager then click Control Panel, System and Security, and then, under System, clicking Device Manager. Administrator permission are required for this action. If you’re prompted for an administrator password or confirmation, type the password or provide confirmation.
Go to the list of hardware categories and find the device that you want to prevent your computer from waking up, and then double-click the device name. Click the Power Management tab and then clear the check box saying, Allow this device to wake the computer.
To prevent programs from waking your computer
Beside an devise that could be keeping your computer out of his sleep, it might as well be an program or scheduled task. By default, Power Option settings do not allow scheduled tasks to wake the computer from sleep or hibernate. However, some programs might awaken the computer if these settings have been changed.
Open Power Options, click Control Panel, then go to System and Security, and then click Power Options. On the Select a power plan page, click Change plan settings for the plan you are currently using. You to the Advanced setting tab, expand the Sleep option and there go to the Allow wake timers. Choose Disable for both when your computer is running on battery and when it’s plugged in, and then click OK.