Microsoft had intended to sponsor a special episode of 'Family Guy' to promote Windows7. However, apparently after a screening of the episode, Microsoft decided to back out. It seems that after 10 years and 120 episodes, Microsoft had no idea that 'Family Guy' was full of 'controversial material'. The episode will still air and is looking for another sponsor. (Hey Brad, ya reading this?)
All that's left of the now defunct partnership is the video below from the WIndows 741 Student site.