Clean install in UEFI mode

Hi

I am about to receive the bits to upgrade my husbands PC from a simple desktop machine to what the PC Gamer site assures me is a high end gaming machine. However, in the process I want to take the opportunity of also upgrading to a UEFI system from MBR but I'm a little confused on how to do it.

I've done a search of the internet and found what seems to be a confusing number of ways of doing this. I've got a bootable USB containing the source files which I understand is capable of installing to either UEFI or MBR. Now I think its just a case of simply installing to an unallocated but GPT initialised disk or is there something more involved like altering firmware settings? Somehow I converted a spare PC we have to UEFI without even trying and have no idea how it happened -- not that I'm complaining mind you, it just took me by surprise!

Anyway, any help anyone could give would be most appreciated. If any further info is needed then please let me know and I'll do my best to help.

Tracey

If you are planning to clean install and have BIOS options to boot Legacy or UEFI you can choose UEFI.
Using a bootable Windows 10 iso you can then boot to the iso and clean install Windows.
This should create a GPT partition on the internal drive.

Clean Install Windows 10

https://docs.microsoft.com/en-us/win...ive-partitions

https://www.microsoft.com/en-us/soft...load/windows10
Download Windows 10 ISO File
Create Bootable USB Flash Drive to Install Windows 10

Windows can be installed as Legacy-MBR or UEFI-GPT.
If BIOS is current set to boot as MBR you may have to set to UEFI.
To install as Legacy-MBR you must boot the installation drive as Legacy.
To install as UEFI-GPT you must boot the installation drive as UEFI.
If you use the Boot Menu (F12 during POST on Gigabyte) you will see two options to boot same drive. Select the UEFI option.

To boot as UEFI the USB drive must be created properly. Use option 1 or 4 on the tutorial.

You can convert a Legacy-MBR installation into a UEFI-GPT without having to reinstall.
Convert Windows 10 from Legacy BIOS to UEFI without Data Loss

Caledon Ken said:

I might suggest Win10 ver1909 rather than 2004.

If you don't have win10 ver1909, you can download from MS using Heidoc tool.

As sources\install.wim is bigger than 4G you have to split it to smaller install.swm files

Thanks for all your replies but one thing I would ask immediately is: why 1909 rather than 2004?

As for the other points, well thanks very much for all info but today my husband said he wants to retain his current installation of Windows so he doesn't lose program related files such as those contained in patches and updates for which he doesn't have the source files. This goes against my beliefs that a fresh install is safer but apparently it can be done and there are programs available to assist with this (as a minimum, Shadow Maker from Minitool and AOMEI Backupper). Since have Shadow Maker I shall give it a go and if it works, convert his system to UEFI at a later date. I'd appreciate any comments on this if you have time.

In the meantime I'd be very interested as to why use 1909 instead of 2004.

Tracey

Ver 1909 is stable and is working well.
Ver 2004 is more like a beta release to be developed and polished by "volunteers" like you.
Known and Resolved issues for Windows 10 May 2020 Update version 2004

sygnus21 said:

So I'm guessing you're be on 2004 as soon as you can get it?

Regardless, you're (general) not getting it anyway unless Microsoft approves of your PC so what's the issue? And BTW 1909 had the same reactions... not worthy. Now that 2004 is here, suddenly 1909 is the greatest thing since sliced bread

The same thing will happen with 2004 when the next upgrade is released... it'll be garbage and 2004 will be the greatest

I already have Win 10 ver 2004 but my Win 10 isn't my main OS. I still use Win 7 (for same reason).
As you say, after some corrections, ver 2004 will be a good OS as 1909 is now. If ver 1909 has everything you need, why install ver 2004 that still has issues?