OK it's been a while since I muttered anything ... so here's a start. I was rather shocked to discover that Windows XP does not include DVD playback! This has been a standard feature of Macs for as long as I can remember. (It arrived in Mac OS X 10.1 in 2001) Guess I have been taking my Mac for granted.
Realistically if you bought a Windows laptop with a DVD drive in it then I am sure it comes with the DVD codec (well it should).
Just shows how our expectations rise over time.