OK, so it turns out that Office 2007 Beta 2 won't just not install on my Vista Beta 2 test box, it won't install on my XP Service Pack 2 machine either. Apparently, "The language of this installation package is not supported by your system." WTF!!!
Well, alright, by Redmond's standards I may have a "non-standard" installation in that my language settings are UK English not US English. But EN-UK and EN-US are really not that different from each other. Maybe the ISO file I downloaded from the Microsoft Beta Experience site is cooked. Actually, that's probably the case because the Beta 2 image I have from a PC Plus coverdisc seems to work better. But it still doesn't work right with Vista Beta 2. I think I'm gonna pull the plug on Vista for now. It's just too much effort for too little reward.
Maybe I'll do some testing of ReactOS or AROS on my dev/scratch machine, instead. I may even look into a *nix instead if I can be bothered. My current favourties run to Ubuntu and OpenSuse but I'm always open to new distros. The only major drawback with those is that they generally don't have particularly good development tools.
Oh well, guess I'd better start looking through my OS discs to see what I'm gonna be testing next.