1. "Most existing software is not compatible with Vista. You will have to purchase upgrades to almost all the software you run and many programs will never be upgraded to Vista." - probably true but weak without cites.

2. "It's an exercise in frustration to try to upgrade an XP computer to Vista. Few Vista drivers are available except for new devices designed for Vista, and manufacturers don't plan any." - see point 1

3. "Vista Home Basic, shipped with lower cost consumer market computers, is rather minimal" - you need to do an elevator pitch on what this means.

Overall, it's pretty good. I'd be inclined to attempt to reduce word count where possible in order to maximise impact. I think Drew picked up all the grammar and spelling issues.