>>408341394
check your BIOS settings for anything referencing CSM or Legacy BIOS (iirc)
varies by manufacturer of course but you'll know its in legacy mode if it doesn't let you switch on resizeable bar-relevant options
best bet is to try and follow instructions to enable resizeable bar on your motherboard and then see if you need to convert after trying
that said: if you are in legacy bios mode now and switch your windows may become unbootable until you switch it back so don't just tick it off without converting if you do find that it is enabled