Three and a half years after being released, Windows 10 has finally toppled Windows 7’s to become the most popular desktop operating system on the planet. That’s according to the December OS market share statistics from analytics firm Net Applications, which show that Windows 10 managed to grab 39.22% of the market, while Windows 7 lagged behind at 36.9%. It’s the first month ever in which Windows 10 has been on top.

This is notable for a variety of reasons, the first being that Windows 7 managed to sustain its lead for as long as it did. Coming on the heels of the disastrous Windows Vista, it’s no surprise Windows 7 quickly shot to the top. Then, when Windows 8 underwhelmed, millions opted to stick with Windows 7 rather than upgrade.

The other important factor here is that Microsoft’s extended support window for Windows 7 closes on January 14th, 2020 — just over a year from now. There are still millions of individuals as well as businesses that have yet to move on from the ten-year-old operating system, but Windows 10’s rise to the top of the market share list at least suggests that the market is moving in the right direction as Microsoft winds down Windows 7 support.

It will be interesting to see how Microsoft handles the end of extended support for Windows 7, with such a huge swath of the market still using the aging OS. When Windows 10 arrived in 2015, anyone with a genuine license for Windows 7 or Windows 8.1 was given the option to upgrade to Windows 10 free of charge. Although this offer officially ended on July 29th, 2016, it is still technically possible to go through the process on a Windows 7/8.1 PC.