Each and every month, Steam conducts a survey to collect data about what kinds of computer hardware and software its customers are using. And according to the March survey, the most popular OS is Microsoft’s Windows 10 64bit. In addition, NVIDIA and Intel are still dominant as most PC gamers are still using Intel’s CPUs and NVIDIA’s GPUs.

http://www.dsogaming.com/news/windows-10-64bit-is-the-most-popular-os-according-to-steam-survey-nvidia-intel-still-dominant/

Thats amoung PC gamers though... avg pc user its probably lower than those 37%.

Well "gamers" in a sense. I found steam installed on PCs in some offices just for some pinball or card game or anything like that during breaks.

Also, it includes many, many casual gamers. Otherwise, there would be no chance in hell Dualcores, CPU speeds below 3 Ghz and GPUs with just 1GiB of VRAM would be on top

As such, the install base is pretty representative.

Btw, I still prefer Win7, just like many gamers do. I'm pretty sure gamers are actually pulling down the number instead of up. Might change when DX12 becomes widespread in usage, though.

I doubt that many offices will allow their employees the installation of Steam or games.

I'm pretty sure you are wrong. Microsoft just announced 270 million active Windows 10 licenses and the whole PC market is bigger than 1 billion, so Windows 10 can't be over 25% yet.

NetmarketShare sees Windows 10 around 14%, StatCounter has around 17% internet traffic from W10-devices:

Private households and especially PC gamers are the early adopters of Windows 10, not the business sector.

-------------------------------------------------------------------------------------------------------

Without OSX (3.32%) and Linux (0.85%) systems, the Windows-percentages are this on Steam:

Windows 10 64-bit (38.6%) is now the most popular OS at Steam, Windows 7 64-bit (34.5%) is second place.

If we count 32-bit and 64-bit versions together, Windows 7 is still in the lead with 41.7%, followed by Windows 10 with 40%.

DX10-incompatible systems (XP and older) are now only 2.13%

Lol this is so fake Windows is no longer the most popular OS and hadn't been for quite some time.
Linux based OS are by far percentage wise the most popular OS among users worldwide.

Steam just doesn't run on the most popular OS.

Yeah, Steam doesn't run on Android smartphones. But we are talking about PCs here.

Or do you claim, Linux based OS also dominate devices bigger and more powerful than smartphones? Then please show us some proof.

How about web servers?

http://www.w3cook.com/os/summary/

I think they are more powerful, than a smartphone ;) Even though his argument is incorrect, Linux is the most widely used OS today. Windows has only significant lead on the desktop market.

Even if every web server in the world ran linux that would not be enough to make a difference. Web Servers are a far smaller total than desktops, not to mention in even web servers MS has a significant share of the market..

And how many web servers are there worldwide? Also a billion?

Netcraft counts around 6 million web servers, that's a bit less:

This is a Steam survey and it seems like people discussing everything but the Steam survey.