Blizzard Entertainment announced on a World of Warcraft Forum post that they will be ending support for two operating systems. Those systems are Windows XP and Windows Vista. If you are still using one of those operating systems, you are going to need to upgrade if you want to keep playing Blizzard’s games.
The Forum post was posted by Community Manager Ornyx said:
Starting later this year, we will begin the process of ending support for Windows XP and Windows Vista in World of Warcraft, StarCraft II, Diablo III, Hearthstone, and Heroes of the Storm. Microsoft ceased mainstream support for these versions of Windows in 2009 and 2012, respectively, but since a decent portion of our audience was still using them at the time, we continued supporting them. However, there have been three major Windows releases since Vista, and at this point, the vast majority of our audience has upgraded to one of the newer versions.
Community Manager Ornyx points out that when Blizzard ends support for Windows XP and Windows Vista, their games will not run on them anymore. Players who are still using either one of those older operating systems should upgrade to a newer version.
Blizzard is going to roll out this change on a staggered schedule, which should give players who are currently using Windows Vista or Windows XP time to upgrade their OS. Additional notices about this change will be posted as Blizzard gets closer to making that change for each of their games.
Microsoft ended mainstream support for Windows XP on April 14, 2009 (with extended support ended on April 8, 2014). Microsoft ended mainstream support for Windows Vista Service Pack 2, on April 10, 2012. Extended support for Windows Vista Service Pack 2 will end on April 11, 2017.