keyboard messed up?

Either caps lock or a stuck shift key.

It's nothing to do with language settings. Unless your shift key is physically stuck down, it's as rerunx5 says.

Some keyboards [mine] come with a loading disc. If yours is the same, try reloading the keyboard into your computer using your disc.

Have you tried getting back to the 'filter key' and doing everything again in reverse?

take the shift key off then check to see if its stuck down

You don't say which country you are in but when I set my Windows installation up, I forgot to change my keyboard settings to the UK and set it to US. This means that by pressing @ I got ". Try that. If that happens then your keyboard has been set to US. This is a minor thing but unfortunately I don't know how to put it right without re-installing windows. Perhaps someone else when know a more simple way of rectifying?

you have Sticky Keys on to turn it off press Shift key five times

and to disable http://www.ofzenandcomputing.com/zanswers/463

You put it on caps lock. Hit caps lock again to make it go away. it is on the left hand side and above the shift key.

start,control panel,languages and reset it to english or american or where ever you are sounds like its gone back to factory default xx