I guess your "use by" date has passed...
From the 2015 Stackoverflow developer survey:
1) The first Microsoft specific technology was #4 in usage, behind Javascript, SQL and Java (C#).
2) Swift, Apples new language, won "most loved", C# was ninth on the list.
3) Windows did win "desktop operating system" with 54.5% of the total, but MacOS X was second with an extremely respectable 21.5%. What do you think the trend is? Besides, corporations run behind the curve on technology...
4) Finally, the breakdown of what these developers were doing doesn't look good for Microsoft long-term. 57.6% were doing web or mobile development, versus only 9.1% doing desktop development. That is a great recipe to remove Windows from relevance.
Don't bother to thank me for the education. :-)
I've almost given up trying to educate them. While they are installing updates, and scanning for viruii, I am working with my Mac.