My point is that Apple doesn't try to produce the perfect computer for everyone, and this ad targets a market that wouldn't be seriously considering a Mac anyways.
It's not that Microsoft targeting the affordable market is a bad decision, just that it's kind of unambitious.
This was a 'her situation is similar to me' type of ad mixed with an 'incentive to find exactly what you need'. Arguably, two very potent advertising concepts executed in a short and effective commercial.
The targeting of these 'i'm a pc' ads and this particular one is 'I'm a person, with dynamic requirements as to what I need in a computer, one of those happens to be a 17" screen on an affordable laptop'. Contrast this with the Apple ads. There are people (read: average consumers) that see those ads and then walk into the Apple store (without knowledge of all the particulars that comprise the Mac experience) and think "wow, these are really nice, but a bit out of my budget". They then go into Best Buy, see something in their price range, and settle on that. I'd be willing to bet this happens everyday. More often than not, these are satisfied customers who could really care less about owning a Mac because they didn't just pay $1799 extra for a similar (in their mind) machine.