New acer says password incorrect
Try a system recovery, if it has a recovery partition. Remove any madia,DVD, CD, USB, etc. Unplug, remove battery, plug in, push the on/off button, immediately prees and hold the ALT+F-10 if that doesn't work, reboot and use F-10, to load the restore/recovery software, do a factory recovery to return to factory settings. You may want to write down the password and put in a safe location, or put your user name with a administartor password to override.