Let it drain fully (the battery) and remove the charger cord. So that it is completely powerless and will turn off. Then plug it in and try turning it on. If it doesn't, or goes right into hibernation again, then I would try unplugging the power again, let it turn off fully, again, and when you go to restart it, do so in "Safe Mode". This should get you around the issue and let you get into windows to check the sleep settings.
That said, if even that won't work, then there may be something on the computer (malicious software) or a hardware issue preventing this.
How to enter "Safe Mode" when booting the computer.
In Windows 8 and 10 ...
As your computer restarts, press F8 (possibly a few times) to enter "Safe Mode"
a. Press the "F4" key to Enable "Safe Mode".
(The computer will then start in "Safe Mode" with a minimal set of drivers and services.)
b. Press the "F5" key to Enable "Safe Mode" with Networking.
( Once "Safe Mode" with Networking starts, Windows is in Safe Mode, with additional network and services for accessing the Internet and other computers on your network.)
c. Press the "F6" key to Enable "Safe Mode" with Command Prompt.
(In "Safe Mode" with "Command Prompt" starts Windows in Safe Mode, with a Command Prompt window instead of the Windows interface. This option is mostly only used by IT professionals.)
Now sign in to the computer with your account name and password. (If you have one set.) When you are finished troubleshooting, you can exit "Safe Mode" restarting your computer.