Computers don’t wake from sleep or hibernation for ‘no reason’. There is always a reason. Here are some of them.

If the computer starts to go into sleep or hibernation, but immediately wakes up again, suspect a driver issue, especially with regard to video and network card  drivers. The general fix is to upgrade to the latest drivers.

If the computer goes into sleep or hibernation, but wakes up at some period after, there is a device attached to the system which is set tot be able to wake the computer.

How to find it..

You will need to access the Command Prompt and run it in administrator mode. I have CP attached to the Start menu and set to run in admin mode, but don’t do this if your computer is used by others.

1. Locate Command Prompt, right click on it and select ‘run as administrator’
2. Type in this command  <powerdfg –devicequery wake_armed> Omit the parentheses when typing the line
3. Press <Enter> and you will be presented with a list of devices which can wake up the computer

The most likely devices are USB mice/keyboards and network cards.

How to disable the unwanted functions.

Control Panel > Device Manager > go to each device > right click and select ‘Properties’ > click on the Power Management tab > Deselect ‘’Allow this device to wake up the computer’ > Apply and then OK to exit..

If you are wondering how to get out of sleep or hibernation mode after disabling the above, don’t worry. All you have to do is lightly press the main power button.

I haven’t found that applications scheduled to run at times when I have hibernated the system have any part in waking the computer. They are more likely to remain dormant until you ‘resume’ full operation, so I don’t feel that there is any need to change their settings.

Now you should be able to sleep well knowing that your computer is doing the same..