How do I reset the open firmware password on my Mac?

"Hi! This machine has an open firmware password enabled, which is similar to a BIOS password on a PC. This is not the same as the admin password, i.e. it's in the firmware of the machine itself, and not something on the hard drive.

Basically, this means that a previous owner of the machine decided to lock it, and this lock will prevent you from booting to other drives, optical media, etc. If you know the password, you can go into open firmware and disable the lock. Otherwise, there is a procedure to override it: You need to change the amount of RAM in the machine (either add memory or remove existing memory in the expansion slot), and IMMEDIATELY, i.e. the first time booting after changing the RAM, reset the PRAM three times in a row. That means it needs to chime three times after the power-on chime. Once you've done this, you should no longer see the lock. It's Apple's ""top secret"" way to bypass an open firmware password."

"I went nuts trying everything to get the ""reset RAM"" trick to work on My 2009 2.66 MacBook Pro, and partly by luck, I finally got the EFI PW to reset.

I had to remove the bottom RAM Piece, and boot it with just only the top positioned RAM in it. . Just removing the top RAM piece was NOT working.

Also if you have only one RAM piece, and dont want to buy another, try repositioning the RAM, into the other RAM position to reset the EFI.

I hope my comments helps someone as much as it would have helped me 2 weeks ago.

BEST !"

Sorry folks but there is no way to by pass lock screen (EFI) if you have got a new mac (air, book pro, or what ever) since early 2011. The main reazon is that every singel password is saved in to the bios (i know, i know…) well the little chip that serves as a bios (still it is actually a bios) that you have to remove and then get a new flashed one... if you found it.

Not certain this is your situation, but you might want to check out the answers to this question for advice on how to get access to an OS X computer if you've forgotten or don't have the administrator password: how do i reset my administrators password?or reset the whole thing?

"I'm currently struggling with this on a refurb mac mini... I installed XP yesterday and now I can either get to the password/lock screen or just xp... My problem gets worse, my time machine drive is now throwing the click of doom so if I can't get back to my mac side and have to get an os disc (didn't come with os or gray disc) I lose everything, including emails I've been saving since 2002! Ick

Anyone know how much the apple store might charge to ""reset"" this?"

"thishelped alot .My laptop was under my couch for 8mths.

Thanks"