According to this article http://www.computerworld.com/action/article.do?command=viewArticleBa you really need 4GB Ram to run Vista. MS claim 512MB should be sufficient, but it probably would only give you the juice to load up Vista with no power to run any applications.

My problem here is that with my recent computer purchase I managed to get a 2GB system together of which I'm pretty proud (£500+ without monitor), and it provides me with amazing / enough performance on my XP system. But is it really already too old!!

It just emphasise the need for supported lower spec operating systems. How long is MS going to maintain XP? Good thing I have a Linux box as well, so I'll be able to manage 😉