Windows 10: why can't I install windows 10 pro again with the same computer system?

my system:

Windows 10 pro (64-bit)

cpu: intel corei7-4790k @4.00 GHz
OS: 64-bit OS, x64 based processor
motherboard: Asus Z97 pro
display card: Nvidia Geforce GTX 960

Some years ago I bought Windows 10 pro (64-bit) DVD ROM with CD key. I installed it successfully to a new WD 2TB HDD and it was then activated successfully too.
Now its running speed slowed with new apps installed and successive upgrades of windows to the most recent 1903 version.

I am using the same computer hardware to install a new windows 10 pro HDD.


So, I bought a new WD 2TB HD. I disconnected all other HDDs except the newly bought HDD and the DVD ROM drive and tried to install windows 10 pro on it by using my same DVD ROM as before.
This time curiously it failed.
The message was that my system was UEFI and windows can't be installed on a MBR HDD.

I then bought a new WD 4TB HDD and tried the same install process. It failed again.
This time the message was that my system was UEFI and the HDD was GPT and windows cannot be installed on a GPT HDD.

I tried again a few times using these disks. It failed repeatedly no matter whether I formatted the disks prior to installation or not.

Why was my first Windows 10 installation successful while latter installation invariably failed using the same Windows 10 pro DVD ROM on my same computer hardware?

I even downloaded the Windows 10 on to a 8GB USB stick using Microsoft media creator.
The install failed again though the USB stick initiated the same installation process.

May I know how can I install another windows 10 pro on to a new disk on my same computer system.

Do I need to uninstall windows 10 from the slowly performing HDD before any installation of windows to any new HDD?

:)

 

Clean Windows 10 (?PRO?) install

I have bought a legit "Windows 10 Pro" key of a key website. It is legit since i'm currently using it for over a year now. I currently have Windows 10 Pro installed on my PC and I want to do a clean install. I just can't find the windows 10 Pro download in the tool. But if i could use a windows 10 pro key with a normal windows 10 install, I'll be good to go.

 

windows xp installation and dual core am

could someone please list the steps they follow to install windows with a dual core processor and windows xp service pack to. I'm reletively new to amd dual core and i feel i'm missing a step. All help will be appreciated. thanx

 

Clean Windows 10 (?PRO?) install

As far as I am aware there is no Windows 10 Pro version.
But I'd be happy to be wrong.