Windows 10 passes the 15-year-old Windows XP in popularity

Windows 10 came out in July 2015, and it's already achieved a major milestone by Microsoft's standards.

It's now used on more PCs than the 15-year-old Windows XP, as you can see in this chart from Statista based on NetMarketShare data.

Why has Windows XP been so remarkably persistent?

First, companies loved it because it was the first Windows PC operating system to be based on Windows NT technology - the same technology that Microsoft had used for servers and high-end business PCs called workstations in the 1990s.

Second, there was a five-year gap between XP and Vista, and Vista had a lot of flaws so people didn't upgrade.

Windows 7, released in 2009, picked off a lot of the XP holdouts, but there are still enough left that passing XP is somewhat of an achievement.

By way of comparison, Windows 8 and 8.1. combined didn't pass Windows XP until May 2015 - nearly three years after Windows 8 was released.