On this site there are a lots of questions about setting up Ubuntu on a virtual machine. That rouses a question: why doesn't Canonical release "official" virtual machine images for Ubuntu?
In my opinion, the easiest way to try Ubuntu (as a Windows user) is to download a vmware image and run it. Just a click, and it works :-).
At present, you can find virtual machine images from internet forums, for example, I downloaded this: http://www.trendsigma.net/vmware/ubuntu1104.html
and it works great. But it would be more convenient - and secure - if some images were available on the official site. A torrent file would be enough, that would eliminate bandwidth problems.