Unlocking 4th Core on Phenom II 720 BE

[offthehookah]

It doesn't seem to be working, I went through the bios on my (Asus m4a79xtd Evo) set ACC to Auto, then tried all cores and used unleash cores but nothing happened. Before one says that my fourth core might be defective and thus unusable I wanna say that I bought this board used and as soon as I set it up with my build the fourth core was automatically unlocked (but I had a few problems getting the OS to boot so I just updated bios I should have gone through the BIOS and found the underlying problem. Anyways does anyone know how can I unlock the 4th core? Do I need a specific version of the bIOS?

 

[offthehookah]

I managed to unlock the 4th core however I'm not able to boot into windows, the screen stops on starting windows and the logo keeps moving and forming..
Does this mean my core is defective?

im runnin windows 7 ultimate

 

[enzo matrix]

I managed to unlock the 4th core however I'm not able to boot into windows, the screen stops on starting windows and the logo keeps moving and forming..
Does this mean my core is defective?

im runnin windows 7 ultimate

Yes. You could always still try increasing the voltage or reducing the clockspeed and see if you can boot.