My Mac keeps saying iTunes "has not been correctly localized for this language, run the English version." help!?

I've been trying to open my iTunes on my Mac and this message keeps popping up:

"This version of iTunes has not been correctly localized for this language. Please run the English version."

The problem is that I have not installed iTunes in any language other than English since I first installed it back in 2007. I check for monthly software updates and recently just updated whatever it said I should, possibly including iTunes, but I can't imagine why in the update the language would have changed. I'm not very good with technology, and tried to Google this, but all that kept coming up were people in other countries having trouble with installing iTunes in other languages. I'd appreciate any tips/explanations!

Oh, and I don't have any of the software CD's that came with my computer or iPod when I first got them, they are all at my parents' house.