change grub setting from readonly to normal
9981
How do I get permissions to edit system configuration files?
51288
Cannot get grub menu to timeout (or go away)
121308
How do I get the GRUB menu to show when starting my dual-boot system?
48941
How is /etc/default/grub generated during installation?
84732
How to get GRUB to be the default bootloader instead of Windows Boot Manager on a UEFI laptop?
64198
How to update grub on a dual boot machine?
53804
How can I prevent Windows from overwriting GRUB when using a dual-boot machine
62421
/usr/sbin/grub-mkconfig: 1: /etc/default/grub: If: not found
148397
How do I modify my boot options in Windows 8?
144330
Is there a way for grub to automatically reboot into Windows from Windows?
57063
How do I change file system in recovery mode to read-write mode?
39257
How to delete GRUB entirely from GRUB rescue and boot Windows only
32543
How can I add the Memtest86+ options back to the Grub menu?
104432
How to set previous kernel as default in GRUB (Grub customizer)
107012
How to get info on my current GRUB / boot configuration?
40939
How do I customize the GRUB menu?
93257
How to disable Boot menu (F10-F12) on laptop?