Ian McDonald recently posted a retrospective in honor of the 20th anniversary of the release of Windows XP. Because Windows XP didn’t age well in the era of exploding Internet security threats we have a tendency to demean it. But if you are looking at it in 2001 is was a sea-change release that strongly met customer needs. It would take over 8 years until a worthy successor emerged in the form of Windows 7. It would still take years for Windows XP to fade from general use, and it is still used in some embedded systems. BTW, Ian was still one of the leaders of Windows, though on the separate Windows Server team that released Windows Server 2008 based on the same Core as Windows 7. He was still plugging away at Windows Server when I left Microsoft in 2010.
Since I didn’t start blogging until after leaving Microsoft I never got to write all the good things about Windows XP. My first real blog about Windows XP was decidedly negative. It was a decade after release and XP had become the whipping boy for bad Internet security. I’m not going to try to go back and give Windows XP the glowing review that it deserved at the beginning of the century. But let’s all acknowledge that Windows XP, more than any other software, signaled the transition to 21st Century client software.
To all my friends who were on the NT5/NT5.1 team, congratulations on the 20th anniversary.
Hal's (Im)Perfect Vision 
My Windows XP anecdote. I was working for Microsoft at the time, in Premier Support in the Dallas area. The release team trained up anyone who was interested, gave us a nice polo shirt and sent us off into the local CompUSAs, Circuit Cities and Best Buys to sing the praises of the new OS. Most of the folks I talked to already had desktop boxes running Win95 or Win98.
I’d show couples how they could each have their own account, with their own settings and own browser histories and favorites. At that point, the husband’s ears would perk up and say something like “oh, so I don’t have have to look at her favorites and she can’t see where I’ve been browsing”. It was obvious that the latter half of that statement was what they were interested in. “In Private” browsing (aka “porn mode”) had not yet been invented.