New Windows 10/8.1/8 computers have been set with new UEFI instead of traditional BIOS. And the option "Secure Boot" in UEFI BIOS has applied to automatically prevent malicious software and unauthorized operating systems from loading during the system start-up process. Surely it makes computers safe. However, if it keeps enabled all the time, there will be lots of things you cannot do.
So if you want to do above things, you would have to disable secure boot in Windows 10/8.1/8 at first. Follow 2 steps below to make your computer secure boot disabled (or enabled).
See the article about accessing UEFI BIOS setup. And you would get four available methods, hot key, PC settings, command prompt and Shift/Restart buttons.
While you have accessed Windows 10/8.1/8 PCs, it doesn’t matter which way you choose at last, but PC settings is recommended. And if you are locked out of PCs, the 4th method is better for you.
1. Click the Power icon on login screen. Hold on Shift key on computer keyboard and click Restart button on login screen.
2. Next select Troubleshoot > Advanced options > UEFI Firmware Settings.
You would successfully enter UEFI BIOS in Windows 10/8.1/8 computer.
Different computer brands have different motherboards, so it is a little different to find the Secure Boot option in their UEFI BIOS. But usually you can find it under "Boot", "Security" or "Authentication" menu and change its value.
1. Use arrow key to select the menu that includes the Secure Boot option.
2. Select "Secure Boot" and use "+" or "-" to change its value to be disabled (enabled).
The following are usual operations to disable secure boot in different common computers.
1. Use arrow key to select Security menu, and then use Up and Down key to select Secure Boot Configuration and then press Enter.
Note: If no "Security" tab, select "System Configuration" instead. And directly disable secure boot under it.
2. When Secure Boot Configuration warning appears, press F10 to continue.
3. Use up and down arrow keys to select Secure Boot. And then change its setting to Disable or Enable with left and right arrow keys. Press F10 to save the changes.
Refer to: http://support.hp.com/us-en/document/c04784866
Highlight the Boot tab with arrow keys in UEFI BIOS Setup, and change the Secure Boot item to "Disable" or "Enabled".
1. Enter Boot > Secure Boot menu > Key Management.
2. Select "Clear Secure Boot keys".
3. Change Secure Boot state to be "Disabled".
Note: Because the option "Secure Boot Enabled" is always greyed out, only after you clear secure boot keys, can you disable secure boot. Then you can have the option "Install default Secure Boot keys" to restore the default keys.
Refer to: https://www.all4os.com/windows/disable-asus-motherboards-uefi-secure-boot.html
After entering UEFI BIOS, you have two options to disable secure boot in Acer desktop/laptop/tablet.
On desktop: Highlight the Secure Boot under Authentication and you can change its settings to "Disabled".
1. Go to Security > Set Supervisor Password and create a password.
2. Navigate to Boot > Security and disable Secure Boot.
3. Remove Supervisor password under Security tab and save changes.
Refer to: https://uk.answers.acer.com/app/answers/detail/a_id/27071/~/how-to-enable-or-disable-secure-boot