Old thread, but...

On all pc's and keyboards I've been using here (Norway, Europe) ctrl+alt+2 gives @ in every software except Word. I even have a MS Side-Winder X4 keyboard, and @ is marked and placed on the #2 key, and to the right of 2 - which indicates ctrl+alt to activate it. So, in that respect I'd say Ctrl+Alt+2 is std Windows shortcut for @ in this area.
Though as have been said above, using AltGr+2 will give @ in Word

Regards