Have you installed French language support?
Open a blank document (in Word, for example) and instead of typing the accented letter, hold down the ALT key and type 138 on the numberpad (not the top row number keys above the letters). This will print out 'e with the grave accent'.
ALT+133 for 'a with the acute accent' , ALT+147 for 'o with circonflex' etc
These are ASCII codes for letters not commonly found on the keyboard, but French Windows should be able to handle accented letters without having to resort to this method. :4-dontkno
è à ô ... do you see the letters on the left? They were typed in the English version of Windows using the ALT method.
EDIT: To install a French keyboard, go to Control Panel > Keyboard > Language > Add