Hello ,
Good to see you in Microsoft Community.
Firstly, could you let me know the specific system version (OS Build)? You can check it by pressing Win + X > System > Windows specifications*, click “Copy” and paste it in your next reply*.
Did this occur recently, or has it been going on for a while? If it was recent, did you have any special actions (such as installing system updates*,* hardware changes*, etc.*) before that?
Based on your description, the message "Now entering power save mode." you are seeing should be from your monitor and not the Windows system, which is normal. Most monitors do display a similar message before the system has successfully booted. If you would like further information, I suggest you contact the manufacturer of your monitor for assistance.
Or you can Reset and Restore default Power plan to default settings. Previously customized power plans would be removed. Run Command Prompt as an administrator ("Win" logo key + "Q" to open Search box*, type"Command Prompt", select "Run as administrator"), and copy and paste the following commands into the* Command Prompt and press Enter to run, then reboot to see if it works fine.
powercfg –restoredefaultschemes
You may also Perform a clean boot **** to see if it is normal, this is a troubleshooting step. In this mode, we can further confirmed whether it is caused by system problems or third-party software or personalized Settings. So please be patient.
Disclaimer*: A “clean boot” starts Windows with a minimal set of drivers and startup programs. It helps to determine whether a background program is interfering with your game or program and to isolate the cause of a problem.*
These steps of "clean boot" might look complicated at first glance. However, to avoid any trouble for you, please follow them in order and step-by-step so that it will help you get you back on track.
If anything is unclear, please do not hesitate to let me know.
Best Regards,
Mosken_L - MSFT | Microsoft Community Support Specialist