If this your PC see if you can remember it after a good nights sleep
Or contact acer and be prepared to prove you are owner before they help you
The bugs which enabled bios password to be brute forced to crack have been fixed in recent versions and checksum of password is not displayed after a few wrong guesses so there less options of getting round problem
I presume this is a laptop not a desktop PC
Toms rules prevent any one helping you on fear of being barred
Regards
Mike Barnes