According to Netmarketshare, half of all PCs are running Windows 7 while Windows 10 is at a healthy second with 14.35 percent of the market despite being less than a year old. Microsoft's free Windows 10 upgrade for existing Vista and 7 users is still in effect and clearly having a hand in its quick growth rate. The older and less secure Windows XP has finally fallen to 9.66 percent, but is still the third most popular OS.
The remaining systems are running Windows 8 and 8.1, Windows NR, Mac OS X, and Linux. Less than 4 percent of all desktops are running the Apple OS according to Netmarketshare.
The data shouldn't be taken as final, however, due to the huge sample sizes and massive scale involved. For example, statistics from Statcounter show that 20.8 percent of PCs are running Windows 10 while 40.2 percent are running Windows 7. In particular, Windows 7 saw its sharpest decline this past month with an almost equal gain from Windows 10.
The free Windows 10 upgrade program has been partly blamed for slowing notebook sales that has continued into 2016. Consumers are more likely to hold off on purchasing new hardware if existing devices can be refreshed at no cost.
Source(s)
http://www.netmarketshare.com/operating-system-market-share.aspx?qprid=10&qpcustomd=0&qpct=3
Via: http://www.heise.de/newsticker/meldung/Windows-10-verbreitet-sich-nur-langsam-3195407.html