My @ key is in the wrong place, when you click the @ key it comes up with ", and when you click the " key it comes up with an @, also the 'hash' key has vanished, it comes up with a \ instead, and when you click the \ key, its normal.

I've looked in the keyboard settings, but can't find the regional language to changing the keyboard language.

By the way its windows XP, thank you!

Check your keyboard settings.
OPen control panel and look at the regional settings and make sure they are set for the correct country.