Blizzard has just announced on its forums that it will discontinue its support for both Windows XP and Windows Vista in "Diablo 3," "World of Warcraft," "StarCraft 2," "Heroes of the Storm," and "Hearthstone." Those who are still using Windows XP and Vista to play Blizzard's games are encouraged to upgrade their OS to the newer versions if they want to continue playing after this year.
According to the community manager Ornyx's writing on the company's forum, they will start the process of ending support for Windows XP and Windows Vista in the said games later 2017. Note that Microsoft ended support for Windows XP and Vista in 2009 and 2012 respectively.
Ornyx asserted that Blizzard continued on supporting the old operating systems because a decent portion of its player base was still playing games on them. But, Ornyx pointed out that as a vast majority of Blizzard's audience has now upgraded to either one of the newer versions (Windows 7, 8 or 10), the support will now therefore conclude.
This gives a simple indication. It is necessary for Windows XP and Vista users to upgrade their OS to at least Windows 7 or just plainly stop playing Blizzard's widely popular games.
Ornyx further mentioned that as the support for older operating systems discontinue, the games will not run on them. The ending of the said support will materialize on a "staggered schedule." It implies that not all games will be affected at the same time and that Blizzard will post further announcements as it gets nearer to ending the support for each game.
Blizzard has no doubt gets the credit for having supported these operating systems for so long. It's hard to see that many users are disappointed by this announcement because there are not so many people still using Windows XP and Vista. However, to those who are still in the older OS versions, positively it will be much easier for them to make the needed upgrade and continue on the enjoyment of playing Blizzard's amazing games, according to PCGamer.