I have a Dell Optiplex 7020 with 16GB RAM and 512GB SSD running Windows 10 Pro, pre-installed on a refurbished machine from Amazon. I want to install Zorin 16 Pro "alongside" it, so I can boot to either one, getting lots of experience with Zorin before cutting the cord and kissing Windows goodbye. Initially, I burned the 16Pro iso file to a dual-layer DVD, but in order to boot the DVD, I set the BIOS to "legacy" boot, with the optical drive first in boot order. That worked, but the Zorin install said it couldn't find another operating system, so could not do the install "beside" the Windows 10 installation. Windows 10 is in a GPT partition on the SSD, booted with UEFI.
So I used Macrium Reflect Free edition to make an image of the SSD onto a flash drive, in case Zorin messed up the drive.
Thinking that doing a legacy boot of the Zorin DVD caused it not to find the Windows 10 partitions, I then used BalenaEtcher to burn the Zorin 16 Pro iso file to a flash drive, set the BIOS to enable boot from USB, and set it back to UEFI boot. After doing this, booting brought up the Windows boot menu, and I was able to navigate to boot from the flash drive. This worked, and I selected to install Zorin 16. I got to the "Updates and other software" screen, clicked "Continue", and that screen got as far as the fourth progress dot and just stayed there with the washing-machine cursor (for more than 2 hours) before I clicked the "Quit" button. I did this twice and got the same behavior. Here is a photo of the screen:
What can I do? I have no idea how to fix this. Are there some kind of logs I could post so someone could help me figure out what's going wrong, and fix it?