how to troubleschoot irq#15 during linux instalation?

Question

several distributions say the same

Answer 1

You do know it is sort of a hardware problem, yes? It is a very ancient issue I think, newer, PCI-only systems should never encounter this in either Windows or Linux.

But half of all IRQ # can be adjusted in software. This particular IRQ line is used by peripheral devices like sound card, network card, etc. But only one of them can go on using this IRQ #, you need to give the name of the two cards that "tries" to use this. Whatever way you use to solve this issue it sure isn't in the installer program.