Lately, I had some trouble installing a new Nvidia display driver:
During installation of this driver Vista told me that "Age of Empires II Update 2" was not compatible with Vista... Er...? OK.....? The Nvidia installer ended without actually installing the driver and Vista then asked if it should try installing the program with recommended settings? Well, go ahead I thought... Now the Nvidia installer was sure it wasn't running on Vista and quit. I rebooted and tried my luck again - no success. Still the installer quit because it could "run on Vista only" - though I was quite sure I was running Vista at this time! I guess the "recommended" settings emulate some kind of Windows XP environment - but I couldn't turn this off again for this Nvidia installer. Well, I'm sure there would have been a solution to this but I wasn't in the mood searching for it.
My overall impression of Windows Vista: nice OS, I like it, but it needs some updates. I'll maybe give it another try when the first service pack is released.
One thing I don't like about Windows Vista is it's approach towards more security. I can't understand why Microsoft invents things like "AUC" (Advanced User Control) or a "Secure Mode" for Internet Explorer but still the default user has general administrative privileges. Microsoft doesn't bother copying innovations from others so why not copy Linux' user strategy: non-privileged user for every day work and "root" account for administrative tasks? (Of course, this would be possible with every NT-based Windows, but it's not default, may give you a hard time and isn't very comfortable - compared to a little "su" or "sudo"...) I guess it would be easier and even straight forward to develop software which does not need to write to folders other than the user's home folder than to invent something like "AUC"...? With Vista Microsoft would have had the chance to accomplish those changes and make software developers rewrite their applications accordingly, but they decided to re-invent the wheel and like every new wheel it has some edges at the beginning...
For now I'll be running Windows XP as my second OS. No trouble installing applications, no stupid questions all the time ("Yes, I'm sure...", "Yes, I do wan't to...") and "World of Warcraft" runs as perfectly as with Vista! ;-)