Solved! Hi, I've hp elite book 8440p and can't get @ sign but it is indicate on the key with ' and " signs.

Solution
Towards the right hand end of the second row of letter keys on your board is a key with single and double quotation marks. Try that key with your Shift key and see if you get an @ symbol.

It's a keyboard and language glitch.

EDIT: Try the Shift and 2 key. I misread your problem.
Towards the right hand end of the second row of letter keys on your board is a key with single and double quotation marks. Try that key with your Shift key and see if you get an @ symbol.

It's a keyboard and language glitch.

EDIT: Try the Shift and 2 key. I misread your problem.
 
Solution