Think about it. You already tried video drivers, that didn't work to end the problem, now you reinstalled Dx9, and that didn't do it so what is left? Reinstall the game.
Haha, I went through alot of trouble, but you know what? I finally got it working.
First time when I used Driver Cleaner it messed up my computer somehow(I couldn't install new drivers for some reason) and i thought it was my own fault.
Then I reinstalled Vista(Yes, I know I could have fixed it somehow, but i'm lazy + I have time so why not just reinstall? There was anyway lot of junk I loved to get rid of.) Ok, then after I got it installed and installed updates etc. I deleted the old drivers, followed the instructions in readme.txt(of Driver Cleaner) carefully, didn't want to get troubles again. Well it still happened... I got annoyed and installed Windows XP Professional well... again, but this time I had troubles finding any working drivers to my graphic card, because there isn't many of those for XP. But anyway I finally found one, it isn't the latest but my computer runs fine and I reaaaalllyyy was surprised when I tried Oblivion, it worked!
I don't know if I will get more troubles later but this is fine for now.
Thanks for the help anyway!