1 Answer

1) Control panel>Power Options>Power Schemes Dropdown Menu>Always On
2) or do u have a button that says Power/Sleep on the front of the system?

To take the system out of the power-saving sleep mode, press and quickly release the
power/sleep button. The system “wakes up” and returns to where it was prior to going
into the sleep mode.
You can also wake the system by pressing the space bar twice in rapid succession. Note
that you cannot wake the system from the sleep mode by pressing the keyboard’s space
bar once or by moving your mouse, @sstated in your user’s guide.

The power/sleep button is a “smart” switch. It recognizes when the system is in sleep
mode. When the system is in sleep mode, you cannot power off until you press the
power/sleep button again to wake it up from sleep mode. If the system is in sleep mode
and you use the power/sleep button to turn off your system, the system prompts you to
save all data for any opened applications before it shuts down the system.