at boot “keyboard is locked”. age=5 yrs

sorry to be so scanty on info.
what is your opinion?
friend calls with:
trying to boot old computer off for several years.
can’t get past ‘keyboard is locked’ on black screen at boot.
she tried all the F keys. she did not have a new keyboard totry. she can’t get into setup to see if something’s set funny. i tried having her short the battery in attempt to clear BIOS settings but no luck. she is bring me system later today. whatcha think? think BIOS is at fault. sorry no particulars about mboard etc…
thanks in advance for your thoughts…