Question about unlocking characters in SF4

I am kinda new to SF4 and new to this forum.
I have unlocked Fei Long, Sakura, Rose, Dan, Cammy, Gen, Akuma and Gouken, and I’m on the way to unlock Seth.
Now I remember some more characters like T.hawk and Dee Jay. How can I unlock them? is it possible in my game version or is Super Street Fighter 4 is another version that those characters are available only in there?

You have to buy Super Street Fighter IV.
There is no unlocking,

Dee Jay, T. Hawk, Cody, Guy, Adon, Dudley, Ibuki, Hakan, Juri and Makoto are not available in Vanilla SF4, you have to buy Super.

Yup you have to buy super, although if you’re on PC you’re screwed for quite a while. I don’t even think they’ve started building a pc ssf4 version yet.