Idk, in Rufus I set it to MBR (well it set to that automatically if I'm not mistaken) since I didn't know if it would support GPT (it's an old pc as I said), also I only had a single sata cable available so I installed it without the windows drive connected, the error message popped up only after I replaced the drives and tried to boot to the windows one, which wss supposed to be untouched, also as I said no bootable media (I made with Rufus, I could try balena etcher or what you said) but it just skips the boot media when i turn it on, even if i set it to the highest priority in bios (tried Debian, mint, kubuntu, but I'll try fedora to see if it's any different)
When I was making the drives in Rufus it didn't say anything when writing to the drive