When you can't get a computer out of power save mode by any usual means, typically the cause is that the button-cell-type battery of your computer, located on the motherboard, is empty. Usually, this happens on a computer which is a few years old since its batteries will have run out after such a long time.

Why can't I get my computer out of power save mode?
When you can't get a computer out of power save mode by any usual means, typically the cause is that the button-cell-type battery of your computer, located on the motherboard, is empty. Usually, this happens on a computer which is a few years old since its batteries will have run out after such a long time.
What is the shortcut key to turn off power save mode?
click Start button... in the search box, type power options... Enter... in the right side, under Select a Power Plan, where is the blue dot at ? If it is at Power Saver, click Show additional plan.... select High Performance...also, click Change Plan settings... in this window, select the time.