Since remembering the ALT codes for Windows is a bit of a challenge, Microsoft put together a simpler technique for typing accented letters in Word.

For letters with acute accents (i.e. á), press Ctrl+apostrophe ('). Release both keys and type your letter. (Hold down Shift while you type the letter for a capital.)

For ñ, press Ctrl+Shift+tilde (~). Release all three keys and press n. (Hold down Shift when you type N for Ñ.)