Myriad reasons exist as to why users won’t upgrade, but they generally include things like support for older applications, the cost of a new machine or software, and the ease of piracy.
Certain geographical regions seem more inclined to stick with XP, including in China, which banned Windows 8 after Microsoft beefed up anti-piracy measures, and Eastern Europe, where the proportion of users running XP climbs into the 20–30 percent range.
Microsoft released the patch for MS017-10, the vulnerability that Wanna Cry exploited, on March 14—two months before it tore across the world.
The problem goes beyond customers being reluctant to install patches.
Why didn’t the organizations affected by Wanna Cry just apply that patch two months ago?