An ACER notebook does not have a button battery. When the notebook battery is used up or has run out of power after being stored for a long time, the system cannot be found every time it is started. The secure boot + UEFI boot is enabled by default. If it is Win8 or above, it can be started normally. Most of these notebooks should be installed with Win7. Win7 can also use UEFI boot but Secure Boot must be turned off to use it. It is forced to be enabled by default and is grayed out and cannot be turned off.
Press F2 to enter BIOS, go to Security, select Set Supervisor Password and press Enter to set a password.
Return to the BOOT option, Secure BOOT becomes optional, and Enabled is set to Disabled to close.
(Note: After changing the secure boot, you can set the password to blank, otherwise you will be prompted for the password every time you enter the BIOS)
