Verified answer

Your keyboard is setup for the UK. The UK version of the qwerty keyboard has the " where the @ is on the US keyboard. So if you see an @ on the 2 then you have a US keyboard and your language settings have the UK keyboard as the default keyboard.

To change it goto control panel (this is classic view on windows XP, but vista shouldn't be to different). Open Regional and Language options. Click on the Language tab. In the groupbox "Text services and input options" click details. In the box installed services click on keyboard of your default profile (the default profile is listed in bold, assuming you may have more than one) and press ADD. From the list Keyboad layout/IME, select US or United States-Dvorak. and press ok. Then click on the UK keyboard and press Remove. This will set the default input to US. You may get a message telling you the keyboard can't be removed until you restart.

Alternatively you could setup another profile there with the correct keyboard, and switch to that profile. Or if you already have two profiles you can switch

On some pc's the you can righ click on the EN next to the system tray and select settings, to take you directly to the Text services and input options.

Thanks a lot man !!! It was really helpful :)