Read this article
http://www.desktoplinux.com/news/NS3179571720.html
Now there are many things that are wrong here. First of all I ran Vista beta 2 on an old hp computer with a 800MHz PIII celeron processor, 256MB of RAM. Vista ran very dicent on it and I didn't have any problems with it. Second, businesses don't need the Aero theme, so they don't need to worry about it. A computer with the specs described in the article should run almost perfectly fine. Then there's the thing with SLED. It costs about $40 a year for each computer, the business owner will not be saving much money. Then there's crossover office, why in the heck do you need to pay $40 extra?
Also, Vista can actually use flash drives as memory, that guy that wrote this was just...

Another thing, vista will run fine with 128MB of VRAM. But if you want all the eye candy crap in SLED you will need a video card with at least that much memory, and it has to be nvidia or ati, preferably nvidia, as installing the drivers for ati is heck.
And why spend more money on useless software like that transfer crap software? Ever heard of "backing up"?

In conclusion this article is inacurate in most aspects. The writer is an ignorant person who needs to research the facts and actually test stuff. In my opinion the business will save more time and money by upgrading to Vista rather than SLED. There's also a thing that the writter didn't consider. Windows and Linux are not the same thing. There will be training required and there are many applications that business depend on that are not available for linux. Don't get me wrong, I love SLED, but in this situation Vista would be the way to go.