According to data from Valve's Steam Hardware and Software Survey for the month ending April 2014, Microsoft's latest operating system usage has increased to a combined total of 23.66% for both Windows 8 and Windows 8.1. During the month of March, the usage was at a total of 23.03%. For the month of February, it was 22.14%. This factors in both 32bit and 64bit of Windows 8 and Windows 8.1.
This data is collected by Valve's Steam game client, for those that did not know, and measures hardware and software stats on a monthly basis. This data indicates how much share an operating system has (among other stats) when it comes to gaming via Steam.
According to this data, Windows 8 32bit has a share of 0.49%, which is a 0.01% increase compared to the previous month. Windows 8 64bit had a share of 8.86%, which is a 0.28% drop compared to the previous month. Windows 8.1 32bit went up by 0.03% with a 0.41% share, while Windows 8.1 64bit climbed up to 13.90%, with an increase of 0.89%. Windows 7 64bit, on the other hand, saw a 0.25% decrease to 50.02%. Windows 7 32bit holds a 12.37% share.
Just recently, Net Applications released their stats for the month of April and Windows 8 saw a combined market share of 12.24% with Windows 8.1.