Please don't question the efficacy of my computer setup. I can assure you that I know more about software and hardware than anyone else in this forum. Of course Best Buy only sells 2 gig systems -- they know that idiots have to use the systems, so they need the extra RAM.
Yes, Vista is a pig if you don't know what you're doing. Yes, the original SDKs and pre-betas were released four years ago so that software developers (like myself) and driver developers could prepare for it. Vista may have only been released a year ago to the general public, but the people who write Elite have had access to it for almost 4 years.
If you don't know what you're doing, a gig of RAM is pretty thin for Vista. The system I'm writing on right now has 8 gigs of RAM. On the other hand, if you turn off a couple of useless services and get rid of the sidebar, the thing works great with just one gig. Sure, Vista's a little sluggish here and there with older processors, and I wouldn't recommend it for the casual user, but I am not a casual user. My trading machine is an older computer (3 years ago it was a top-notch system) and I am using it as a pure trading platform -- not for games or browsing the web or anything else. As to the possibility of its getting in the way of the software, I have a couple of observations.
First, While using Scottrade Elite, RAM usage never went above 45% and processor utilization hung around 12 to 15% under normal trading conditions. Both metrics are close to ideal. Sctottrade Elite has a very small fingerprint and is fairly well written. GUI response was instantanious, and quotes were more responsive than any I've seen on any other system or platform.
Second, on the same computer with the same OS, MB Trading's software also runs fine, although it takes up more resources than Elite. With MB, RAM utilization hangs around 47 to 48%, and processor utilization stays between 20 and 40%. The point is that even given the inherent inefficiency of MB, execution is far faster and more accurate than with Elite.
P.S. I don't give a darn about Microsoft. I'm not defending Vista, which has some pretty crappy "features" (problems), just defending my expertise. I chose to use Vista on my older computer because it makes a good test platform for the software I give to clients.