I wouldn't even be worrying about the o/s right now. Download the latest drivers for your card and email someone the pic!!!! Those are the two easiest things you could possibly do. You could easily rule out video drivers and the pic being the problem.
If you want help you have help us help you!!! There really is no point going any further until the drivers are updated. I think Vista should be updating itself so that shouldn't be a problem.
One of the key benefits to CS4 is that it is supposed to take greater advantage of video hardware when compared to CS3, which would wrap up more CPU and system memory. Because of that feature, having the latest drivers makes a big difference. That's the reason for thinking that it is a video card driver issue.
I couldn't figure it out either. I thought this was photoshop elements v4 or something.