More info would be grateful, such as:
Do you know the current password?
If yes, you have to enter your BIOS and disable it in the password on startup options.
If not, you need to contact ACER.
(There is an alternative option by XXXXXXXXXXXXXXXXXXXXXXX
But that's a more incorrect way against the rules I think.)
Moderator comment: Yup it's against the rules because it might facilitate use by laptop thieves.