How do I turn on Aero on Vista ?

As title says. I read some guides and I know that from desktop go to Themes, and then from dropdown menu select Aero.

But!... Aero isn't there. Some site said that if Aero isn't there, my computer doesn't support it. That's bs. I have Vista Home Premium, 4GB ram, Phenom II X4 3.0Ghz processor and GTX 260 graphic card.. So Im sure it would work on that

So what's wrong ;< ?

 

a simple google search reveals much check it out because you already mentioned the only other method I know of
http://www.google.com/search?q=prob...e7&rls=com.microsoft:en-us:IE-Address&ie=&oe=