Been running PS on a newly setup Vista-PC (Vista Ultimate X64, 4 GB RAM, GF 8800 GTS) for a few days now without any major issues (except for the occasional missing texture or texture-wiping, which I got on my old system, too).
From what I gather, most problems when using 3D-applications are either hardware- or driver-related.
From my experience, Vista needs at least 2 GB RAM to get it to run stable and fluently when using RAM-intensive software. Even more so when you are using an on-board graphics controller using shared memory.
You should check the following points if you get an error:
1) Check you drivers (graphics and sound) for available updates. Many problems arise from using either old or wrong drivers (i.e. x64 drivers for an x86 system or vice versa) so be sure to get the right drivers for the OS-version you're running.
2) Make sure you have sufficient RAM and the timings and voltage are set correctly in the BIOS. My system would crash frequently at first, until I noticed that the RAM was addressed using (wrong) default parameters.
3) Check your graphics card and make sure it is supported by PS. I've also heard reports of strange behavior in 3d-games when using an on-board graphics card. See if you can borrow an old (supported) card from a friend, install it (don't forget to disable the on-board controller though) and check if problems persist.
4) Check your graphics settings both in PS-setup and in the control panel of your graphics card. Make sure those are set to the correct resolution, try running PS at default settings. Also, both ATI an NVIDIA allow you to change the 3D-settings on a per-game basis. Try fiddling with those.
5) Have you run the updater? If you did and it gave you an error, you might try uninstalling PS and reinstalling from the latest package, then run PS without running the updater first.
6) Make a note of the type of error you experience and check if it is reproducable. Write down any error messages you get and post your findings here - chances are, someone here can help you.
Good luck!
