How to create administrator account?

Install or Reinstall OS X from Scratch

Be sure you backup your files to an external drive or second internal drive because the following procedure will remove everything from the hard drive.

Boot to the Recovery HD:

Restart the computer and after the chime press and hold down the COMMAND and R keys until the menu screen appears.

Erase the hard drive:

1. Select Disk Utility from the main menu and click on the Continue button.

2. After DU loads select your startup volume (usually Macintosh HD) from the

left side list. Click on the Erase tab in the DU main window.

3. Set the format type to Mac OS Extended (Journaled.) Optionally, click on

the Security button and set the Zero Data option to one-pass. Click on

the Erase button and wait until the process has completed.

4. Quit DU and return to the main menu.

Reinstall OS X: Select Reinstall OS X and click on the Install button.

Note: You will need an active Internet connection. I suggest using Ethernet if possible

because it is three times faster than wireless.

This should install the version of OS X that you had installed.

You should probably fix the password issue before upgrading.

Give this a try:

How to Create a New User Account if You Cannot Access Your Admin Account

Reboot the computer. At the chime press and hold down the COMMAND-S keys to start into Single-user Mode.

You will boot to a black screen with scrolling white text, release the keys and wait for it finish.

Enter the following lines at the command prompt pressing RETURN after each:

mount -uw /

rm /var/db/.applesetupdone

reboot

After you reboot the computer you will be taken to the Setup Assistant. When you get to the point where you are asked to setup your new user account, create a new admin account. Be sure to name this user account something different than the admin user account that already exists on the system. When you finish the Setup Assistant, it will automatically log you into the new account.

You can transfer your files from the old account to the new one. See: Transferring files from one User Account to another. Once you have moved all your files into your new account, you can delete the old account using Accounts or Users & Groups preferences.