guardianpk2003 :
So my two options is to
1. Hope it boots up to where I can buy the license and then download Windows 10 from the link you provided and then start from fresh. Ideally.
Or
2. It does not boot up and I'll have to install Windows 10 on a USB and get the license so when I start the pc it recognizes the USB and ask me to install it and start new?
Option 3:
It is highly unlikely to just 'boot up' with the new hardware.
You do not have to purchase the Win 10 license to be able to install it. It will install and run just fine, in an Unactivated state.
From some other working PC, download the Win 10 MediaCreation tool and create the Win 10 install USB or DVD, here:
https://www.microsoft.com/en-us/software-download/windows10
$0
Do a clean install of Win 10, here:
How to do a CLEAN installation of Windows 10
When it asks for the license key, Skip it. It will continue the install and off you go.
Running Win 10 unactivated works just fine, until you buy a valid license key for it.
Restrictions of an Unactivated Win 10 are - No customization of the Desktop or Taskbar, and a randomly appearing nag text at bottom right.
Other than that, it runs just fine.