Windows 10 Install - USB / UEFI / NVMe / OCZ drivers confusion

[hagakure_s81]

Hello all, hoping you can clear up a couple of things for me here...
I've just built a new system, and included in that was a OCZ RD400 M.2 drive (256gb).
I also have the Windows 10 installation USB drive (works for 32 and 64 bit apparently.
Other drives are a MX100 SSD (sata) i'm going to use from my old pc (had the old windows boot on it), and a WD 2TB HDD for storate etc.
The motherboard in my system is the Asus Z270-AR

Now what I did was load up the UEFI/BIOS on first startup, change the boot drive to the USB drive and restarted. Then installed windows 10. Only after that did I ever read there was a different way to install windows for UEFI.

So since the motherboard is using a UEFI, and I don't remember it showing more than 1 option to boot from, can I assume that I've done that install correctly? Everywhere I look online has guides on creating windows USB drives to load into UEFI by using a windows 10 .iso - but all those guides seem to be from before there was a windows 10 official USB drive.

I would assume since the windows 10 install now comes as an official USB this would be the case, however in researching I also came across the terms MBR / GPT for the disk partition system. Checking my M.2 drive, it shows as MBR. It is under 2TB in size obviously, so is this a problem as MBR is outdated?

Next question centres around the ACHI / NVMe system for these M.2 SSD's. When I look thru the advanced section of the Asus UEFI I find that I can only select Auto or ACHI. I'd definitely like to enable NVMe support for this drive as the motherboard was supposed to support it...

I did download and install Toshiba's drivers for the M.2 as supposedly the intel drivers don't support the drive fully, but obviously that is after I installed windows in the first place

Advice?

 

[photonboy]

1) UEFI - the main advantage to being fully UEFI is:
a) possibly faster boot times, and
b) secure mode (if motherboard supports which most do know I think) to prevent boot-time malware attacks (software downloaded through net but can create code that sneaks in during BOOTUP. It doesn't work with Secure Boot enabled)

2) Must reinstall to switch to it. Basically DISABLE CSM (compatibility support module) prior to reinstall and it should now work.

3) You can verify if SECURE BOOTis working.https://www.eightforums.com/tutorials/20208-secure-boot-confirm-enabled-disabled-windows-8-a.html

If "SECURE BOOT STATE" is OFF then you'd need to reinstall without CSM.

4) AHCI?
I'm guessing just select AUTO but I'd have to look at the motherboard manual. What MOTHERBOARD is it?

OTHER:
When I reinstalled Windows I had a PROBLEM. I was trying to login and it was giving me weird errors (I forget). I finally discovered it had automatically put in my USER NAME (e-mail) and Password login info. I was already logged in! WTF?

That never happened months ago so it's either a fluke or that's just how the newer versions of Windows do it.

 

[hagakure_s81]

I'm guessing just select AUTO but I'd have to look at the motherboard manual. What MOTHERBOARD is it?

Thanks for your info. I'll look into that CSM now.
Motherboard is Asus Z270-AR