(http://mos.futurenet.com/techradar/classifications/computing/software/operating-systems/custom-install/install_vistalizator-420-90.jpg)
Who says you need the Ultimate version of Vista or Windows 7 to switch installed languages? Vistalizator extends this functionality to lesser versions too. The link above reveals how you can incorporate Vistalizator's functionality into your installation disc to save you the bother of setting it up on each subsequent reinstall.
http://redirectingat.com/?id=92X363&url=http%3A%2F%2Fwww.froggie.sk%2Fdvd.html