You can set charset to Unicode or Windows Codepage 1252 to type French characters. If you choose Unicode, you can also type Vietnamese. If you choose codepage 1252, you cannot type all Vietnamese letters.
If you want to type both French and Vietnamese, set keyboard mode to "1. Auto combine (Viet)" and charset to "4. Unicode" as follows:
If you want to type French only, set keyboard mode to "2. Combine On Request (English)" and charset to "4. Unicode". Note that the smart Viet Option Page is no longer active because WinVNKey knows you will not type any Vietnamese text.
Enable French in the left list box
Click on the word French to display a list of all French characters and how to type them in. If any entry is listed in red color, it means the corresponding character is not available in the character set you have chosen. You certainly see a lot of them in red if the character set is VISCII, for example. You must see no red if you have selected Unicode or Windows codepage 1252. If you prefer a different way to type in French characters, you can redefine by clicking on the "Edit File" button.