In Windows XP, open the Control Panel, select the "Regional and Languages"
option, "Languages" tab.
Click the "Details" button. This opens the "Text Services and Input
Languages" window.
On the "Settings" tab, click "Add", and then select the appropriate type of
French keyboard you want. If the appropriate driver is not already on the
computer, you will need the MS Windows disk, so that it can be loaded.
That should do it. If you want to be able to easily switch back and forth,
you can use the "Preferences" button at the bottom of the tab to make that
possible.