Vista- Control panel not working

Hello, I made the mistake of "upgrading" my XP copy to Vista. It took a
while but seemed to work in the end.

I am now at the stage that I can't seem ot get any of the Vista programs
running: "windows photo gallery", "windows ultimate extras", control panel is
greyed out and so is the "run.." button (though it works if I click on it).

I can't display control panel at all.. if I hunt around in the address bars
of windows, I can see it but when I click on it I get nothing but a blank
window.

I also don't seem to have the Vista user interface, mine seems very bland.

Help me out.. I don't really want to have to reformat and try again!!