Hello there! If this the password ***** your user account please follow the steps belwo
• Turn off your Mac.
• Turn it back on and immediately hold down the Command(Apple) and S keys together for 10 seconds to boot into Single User Mode
• When you see the text prompt, type in the following terminal commands to create a brand new Admininstrator account (hitting return after each line). Also, note down the spaces between the commands, like a space between mount and -, space between -uw and / etc
mount -uw /
shutdown -h now
After rebooting, you should be able to create a brand new Administrator account. Then in new account, goto System Preferences > Accounts, select your old account and change/reset the password. Then logout from Apple menu and login to the old account with the new password. Let me know the results please.
If this is a lock that shows up on startup then follow these steps
get one extra stick of ddr3 ram for your mac
take out the ones that are in there
put in the new one
( now here is the tricky part)
Press and hold the Command-Option-P-R keys
then turn on your mac
make sure to hold these keys till your mac reset 4 TIMES
if you do not do one of these steps correctly the password ***** get written to the new ram and we will have to start all over again.