Dual Boot on HP Elitebook Revolution

[Mike R]

Here is my post asking for help on the matter:
https://forums.linuxmint.com/viewtopic. ... 1783c0cae5

I recently purchased a used laptop with a fresh install of Win10 on it. As much as I loathe Win10, it is the standard these days, and that's what came with it.
Installing Linux in dual boot was a lesson in UEFI bios, which I had avoided like the plague until now.

The method is to go into windows, shrink the main volume in either half or enough space for LInux - at least 80G or so - and then boot into a live usb stick for the install.
Rufus is the recommended software to burn the usb stick. Not ever a problem there.

What is a problem is dealing with UEFI. The HP version bios can boot into both UEFI mode and BIOS mode, and you need to know which you have before you begin.
This can be determined by looking at how the drive is partitioned - either MBR or GTP.
MBR is master boot record, whcih is likely BIOS.
GTP is GUID Partition Table, which is likely UEFI.
The difference is the number of partitions that a drive can be split into, with GTP basically being unliminted.

This laptop was MBR, but the bios was set to boot UEFI with compatability mode... something or other, going by memory here.
The solution, after much sufferage, was to set the BIOS to boot into legacy mode.

Once that was done, boot the usb stick, install the OS with the "something else" option, create both an ext4 and (4G) swap partition, and click install.
Then comes a warning about a missing EFI partition. This can be ignored because you are booting in legacy mode, et voila...

U R Done.

To sum up: The OS being installed needs to be installed in the same method as the original OS, either Legacy BIOS, or UEFI, which can be generally determined by how the drive is partitioned, either MBR or GTP.