I think he's referring to the fact that there wasn't a major OS update for 5 years (XP: 2001, Vista: 2006). Every part of Vista was a significant change leadin

I think he's referring to the fact that there wasn't a major OS update for 5 years (XP: 2001, Vista: 2006). Every part of Vista was a significant change leading to a lot of application incompatibilities. App developers hadn't dealt with changes like that for years, so fixes were slower than they should have been. That was a major cause of Vista's poor reputation.