Windows PE 2.1 provides you with a basic environment for booting bare metal systems so you can install Windows Vista on them. This basic environment includes a command shell, commands, and drivers. If you need them however, you can add additional components such as language packs into your Windows PE build environment by importing them using the peimg command. Importing a component adds the component to the component store of your Windows PE build environment. For example, to add the French Base Language Pack from your Windows AIK DVD to your Windows PE build environment, use this command:

Peimg /import=C:\winpe_langpacks\x86\fr-fr\lp.cab c:\winpe_x86\base

Once you've imported the language pack into the component store, you then need to install it using peimg as follows:

Peimg /install=Microsoft-Windows-WinPE-LanguagePack-Package c:\winpe_x86\base

If you're not sure of the full name of the component you're trying to add to your Windows PE build environment, use the /list option of the Peimg command like this:

Peimg /list c:\winpe_x86\base

For more information on deploying Vista, see my series of articles titled Deploying Vista on WindowsNetworking.com, and see also Part 2: Deployment in the Windows Vista Resource Kit, Second Edition from Microsoft Press.