If you’re replacing Ubuntu with Windows, Ubuntu is not involved.
You download your wanted Windows from Microsoft; write it to USB/flash media as per Microsoft instructions, then boot it on your device (booting external media is done according to your actual device make/model; so follow instructions for your device; of the ~25 devices I look after I have 9 different boot procedures for external media).
If your media was written correctly, and you booted as per your device requirements; you’ll be asked to install Windows & it’ll just overwrite whatever OS you have installed.
This is a Ubuntu support area; not a Microsoft Windows support site.
Sorry, I know this is a support page for Ubuntu.
The problem arises when I run it in Ubuntu, and I get that error, and I can’t get past it, as I mentioned, in Ubuntu.
I can’t install Wine or other applications; they install but never start.
When using a flash drive to install Windows or another operating system, it gets stuck on the loading screen that says “Ubuntu loading,” and the process never begins.
You don’t run a windows install in a Ubuntu terminal, as Microsoft Windows is an Operating System, and not an app. You boot the Windows system on your machine & install from there.
You can install windows into a VM (Virtual Machine) and run it there, but then its not the Ubuntu terminal you’re using, but whatever virtualization software you choose to use.
The problem arises when I run it in Ubuntu, and I get that error, and I can’t get past it, as I mentioned, in Ubuntu.
I assume you have the Windows installation executable on a USB stick. You need to boot from the USB stick which may require that you go into the EUVE/BIOS utility and select the USB stick as the first boot option.
What did you use to write the windows iso to the USB flash drive? Ventoy is supposed to work with a windows iso but I have never used Ventoy. One method is to use Disk Image Mounter in Ubuntu (right click the iso file) to extract the windows iso which will show under /media/username. You would then create a partition with an ntfs filesystem on the flash drive, create a mount point for the partition on your flash drive you wish to copy to, mount that partition and copy the contents of the extracted windows iso to the mount point of your flash drive partition. Using a terminal is generally faster but you can use your file manager.