I had problems with fpcupdeluxe before, but when I strictly followed these instructions, it worked for me:
https://youtu.be/Q1BQ_6w8whcAlso watch this:
https://youtu.be/6jJ1FNfLwuU The problem is, you cannot explore this program by clicking some buttons and see what they do.
Immediately a lengthy download starts if you click a button and it fails or you must abort it and ends up with some misconfigured garbage that is impossible to repair for non specialists.
The keypoints are:
Install a SVN client (TortoiseSVN for Windows).
Make a separate folder for the fpcupdeluxe executable, because it will store some ini files there.
Make an empty folder for lazarus and point fpcupdeluxe to this folder and start the installation for the ide and compiler of your choice.
It can run a hour, do not think the program died if nothing happens. If you think it died, you can watch it with task manager and see it has still some % CPU usage, so it did not die. Downloading all the sources needs time but doesnt give much CPU usage, so leave it alone in patience until ready. Do NOT use the "Halt" button.