They were developed by completely different teams.
As an aside - as someone who used ME back in the day, I feel like I honestly had more problems with Vista. ME was a downgrade from 98SE for sure, but I don't remember it being the same level of performance and reliability degradation that I saw going from XP to Vista pre-SP2.
As an aside - as someone who used ME back in the day, I feel like I honestly had more problems with Vista. ME was a downgrade from 98SE for sure, but I don't remember it being the same level of performance and reliability degradation that I saw going from XP to Vista pre-SP2.