Notebook Operating System and Recovery

So I have a fairly old 8460p that i'm trying to keep going so my daughter can use it for learning during lockdown. Recently on start up there is a screen message that states BIOS is corrupt and needs update but it allows me to bypass this and boot to windows.  more recently another screen error message pops up and a brand new replacement wireless adapter gets shut down in boot up and i have to plug in ethernet cable to get internet. CTRL key has stopped working also, although that might be unrelated but explains my poor punctuation. I've tried hp file download at https://support.hp.com/gb-en/drivers/selfservice/hp-elitebook-8460p-notebook-pc/5056942/model/505694... but it says the computer is not supported. also tried google search but not very helpful. anyone know how i can update bios? i'm not a computer whizz so if the replies are in computer jargon you will lose me, but i can follow instructions as long as they are detailed and don't miss out critical steps! many thanks in advance