spanish characters: inverted ? and !

[Jesus Arocho]

Any one know how to set this up consistently?  On my wife's laptop the 
keyboard layout was default US and she could type an accented character by 
simply pressing the apostrophe key and then a letter, although 
cntrl+apostrophe and the letter would also work.  I played around to find the 
inverted ? by changing to alt intl and intl.  I finally went back to the 
default and after further playing I found that: right alt (pressed and 
released) followed by holding the left shift and pressing ? twice worked; it 
also worked for !.  Tried the same on my desktop and it does not work.