ON A MACINTOSH:
Accents: Option e – release – then the vowel that you wish to be accented (é, á, í)
Tilde: Option n – release – n (ñ)
Up side down Question marks: Shift Option ? (¿)
Exclamation marks: Option ! ( ¡)
Umlaut: Option u – release – then u again (ü)
ON A PC:
Go to My computer, click on control panel, keyboard, language, add language, Spanish Modern Sort, Apply, preferences, United States International keyboard, set as default.
Accents: Apostrophe then whatever vowel you wish
Tilde: Shift tilde then “n”
Up side down Question marks: Control alt question mark
Upside down Exclamation marks: Control alt exclamation mark
Umlaut: quotation marks/ u
Windows XP: Go to my computer, click on control panel, click on regional & language, click on languages / detail / Add: Spanish (Mexico) United States International keyboard