Three years and five months. That's how long it has taken Microsoft to grow Windows 10's market share enough to grab the top spot in the desktop operating system rankings. The OS it knocked off the top spot isn't Windows 8, but the nine-year-old and still popular Windows 7.

While it's true to say that Windows 10 is now the most popular desktop OS, it's still a very close run race. According to New Marketshare, in November last year Windows 7 held 38.89 percent of the market while Windows 10 was second with 38.14 percent. In December, the change happened, with Windows 10 increasing to 39.22 percent and Windows 7 dropping to 36.9 percent. That will likely now continue to be the trend, with Windows 10 steadily growing its share as more users upgrade away from Windows 7 through buying new hardware. For business users especially this will be the case.

Microsoft will no doubt be sighing with relief the change finally happened, but there's still a long way to go before it can truly leave Windows 7 behind as a part of its history. As The Verge points out, Windows 7 extended support doesn't end until Jan. 14, 2020.

Meanwhile, Windows 10 doesn't have much competition to worry Microsoft. Mac OS X 10.14 only manages 4.73 percent in third place and Linux is down in seventh place with just 2.00 percent. Microsoft's cause is also helped greatly by Windows being the overwhelming first choice for new hardware at all non-Apple retailers. Budget laptops for less than $600 all using Windows 10 also helps a lot.

Windows 10 is meant to be the last version of Windows, which suggests that the market share breakdown may never again have a change at the top. Unless Microsoft revolts and launches a Windows 11, where would that new contender appear from?