Had a look around the Vista web pages last night and the Vista Advisor. It looks like it will not be a simple upgrade from XP. There are many programmes it highlights that there may be problems or issues with but has big problems with Realtek and Kaspersky virus, both need to be uninstalled then reinstalled after. Some of the things it has problems with came preloaded on the PC suprised there were so many. The promo on the site looks good but that is the top end version not the basic Home version, so will be waiting a bit before taking the plunge.
[Pen] Ouch! A horrid situation however it pans out. It's too long since I was a union convenor and kept up with employment law, but make sure you follow all the procedures properly yourself such as following up internal channels even if you know in advance it won't make any difference. You should also keep records of everything, including as verbatim as possible notes of conversations. Best of luck.