gx270 install win 8 problems

Hello!

I have a Dell optiplex gx270 tower pc.
And I want to install win 8.
I insert te disk, the win logo apears for 2 mins and then i get the 0x0000000a error code. Found out it has to do something with vt-x not enabled.
Tried this: http://www.ehow.com/how_7649523_unlock-v...essor.html

And I don't have this option. I read that the cpu supports it, just that there is no option because the bios is 2007 last version...

Any ideas?