WINDOWS
Windows users have several options; in my opinion, the international keyboard is far and away the best (but there are other options, including ALT codes, listed below).

Using the international keyboard
The international keyboard maintains the QWERTY layout, with the following changes/additions:

1.     To type accent grave (à, è, etc), type ` then the vowel.

2.     Accent aigu (é), type ‘ (single quote) then e.

3.     Cédille (ç), type ‘ then c.

4.     Circonflexe (ê), type ^ (shift + 6) then e.

5.     Tréma (ö), type ” (shift + ‘) then o.
 
NOTE: To type any of these symbols by themselves (e.g., single or double quotes) rather than above a vowel, type the symbol then hit the space bar. For example, to type c’est, type c then ‘ then space then e s t
 

6.     To type French quotation marks «  » use ctrl + alt + [ and ], respectively.

The minor disadvantage of the international keyboard is that it takes a little while to get used to typing a space when you actually want to type ‘ or “. More info from Microsoft

In order to use the international keyboard, you need to set it as your default keyboard - here’s how.

International keyboard (Windows Vista)

1.     Open your Control Panel

2.     If in Classic View, click Control Panel Home in upper-left corner

3.     Under Clock, Language, and Region, click Change keyboards or other input methods

4.     Click Change keyboards

5.     Click Add

6.     Scroll down to English (United States)

7.     If you don’t see a list including United States-international, click + to expand

8.     Choose United States-International

9.     Click OK in each dialog window.

10.   Read Using the international keyboard (above) and, if necessary, Troubleshooting the international keyboard (below).

International keyboard (Win XP)

1.     Open your Control Panel (via Start menu or My Computer)

2.     Double-click Regional and Language Options

3.     Click Languages

4.     Click Details

5.     Click Add

6.     Pick English (United States - International)

7.     Click OK in each dialog window.

International keyboard (Win 95, 98, ME, NT)

1.     Open your Control Panel (via Start menu or My Computer)

2.     Double-click Keyboard

3.     Click Language

4.     Click Properties, Settings, or Details (whichever you see)

5.     Click Add

6.     Pick English International or United States International

7.     Click OK in each dialog window.

International keyboard (Win 2000)

1.     Open your Control Panel (via Start menu or My Computer)

2.     Double-click Keyboard

3.     Click Input Locales

4.     Click Change

5.     Click Add

6.     Pick English International or United States International

7.     Click OK in each dialog window.

Troubleshooting the international keyboard

1.     Double-check the above steps, and make sure that you click OK for each dialog.

2.     Look in the lower-right corner of your computer desktop, where you should see a little box telling you which keyboard you are using. Make sure it says US - International.

3.     If you are plagued by strangeness such as cést when you try to type c’est, re-read the note between numbers 5 and 6 of Using the international keyboard, above.

French keyboard

1.     Follow the instructions above but pick French (Standard)

2.     Switch between the English and French layouts with Alt + shift.

3.     NOTE: The layout of the French keyboard, known as AZERTY, is somewhat different than the layouts of other keyboards - refer to the map of the French keyboard.

4.     HINT: You can invoke the Windows On Screen Keyboard - go to Programs/Accessories/Accessibility/On Screen Keyboard. When you change to the AZERTY keyboard and move your cursor over the on screen keyboard, it will display the AZERTY layout. You can then type the accented letters by clicking on the On Screen Keyboard. After pressing ALT/SHIFT you can then continue typing in QWERTY on the real keyboard.

Canadian French keyboard
Follow the instructions above and choose French (Canadian). The layout of this keyboard is similar to QWERTY, making it somewhat simpler if that is what you are used to. Here is a map of the Canadian keyboard.

ALT codes
If you really don’t want to change your keyboard, you can used ALT codes with the ALT key and a 3 or 4 digit code to type accented characters. You can only use the numeric keypad, NOT the row of numbers across the top of your keyboard - list of ALT codes.
 

MAC

Mac users also have a couple of options. Please note that I don’t use a Mac and that these instructions were provided to me by Mac users. If there are mistakes, please let me know.

KeyCaps (OS9 and below):

1.     Click on the apple on the top left of the screen

2.     Open KeyCaps (a little keyboard will appear on the desktop)

3.     Hold down the option key - the accents will appear and you can click on them with the mouse.

4.     To type ù, for example, hold option, click `, type u. The accented character will appear.

Special character pallet

1.     Click edit

2.     Click Special characters

3.     Keep the pallet open for use in any application

French operating system (Mac OSX):

1.     Go to System Preferences

2.     Choose International

3.     Change the system operating language to French - your OS as well as most Apple software will then use French.