Congratulations, Microsoft (MSFT): your latest operating system is starting to make its mark. According to new data from NetMarketShare, 1.72% of all desktop computers in December 2012 used Windows 8, up from less than 1% in November. Of course we won’t have a real measure of Windows 8’s adoption rate until we see the January numbers since by that time many people will have started using the shiny new Windows 8 laptops they got for Christmas. Overall NetMarketShare found that Windows 7 was still the most widely used operating system in the world, accounting for more than 45% of all desktops used in December, while Windows XP finished a close second with 39%. All versions of Apple’s (AAPL) OS X accounted for 7.1% of all desktops in December, a slight decrease from the 7.3% share that OS X posted in November.