

There was a 64-bit version of windows 2000, but it was never officially released so the first official 64-bit OS and the one that started the slow process of killing 16-bit programs was windows XP 64-bit which I believe was 2002, so assuming the current windows 10 is the last supported that means it'll have taken 23 years for 16-bit support to officially end after it started the process.

Which for the sake of fun will be apx 64 years after the first 64-bit CPU was made. Which at this point my best crystal ball seems to say "out look cloudy". Which would indicate that if historical trends repeat then 32-bit will fade out when something above 64-bit takes over the market. Virtually all 32-bit version of windows support running 16-bit programs, and one of the main reasons to still use 32-bit windows 10 is to run 16-bit programs and windows 10 32-bit is still supported. For the sake of humor / information I'd like to point out that the only reason MS "killed" 16-bit programs on windows is because of the move to 64-bit.
