When World of Warcraft: Battle for Azeroth™ is live, blizzard will no longer support the World of Warcraft game client for 32-bit operating systems. The vast majority of World of Warcraft players are already running the 64-bit version of the game, and this change will allow us to focus on making the 64-bit version as stable and efficient as possible.
If you are using a 32-bit operating system, you will need to upgrade to 64-bit. In most cases (as with Windows 7 through 10), you have the option to upgrade for free, but you may need to reinstall some applications. Check with your OS maker to find out how to upgrade to a 64-bit operating system and what applications will be affected.
WHY THEY ARE RETIRING 32-BIT SUPPORT
As Blizzard says, the memory limitations of 32-bit operating systems can impact the playability and stability of many modern games, and 64-bit operating systems have been industry standard for several years. As with past expansions, we’re making a great many technological updates to WoW with Battle for Azeroth to further enhance the game experience, and the time is right to make this change.
We recommend updating to the 64-bit version of the game before July 1, 2018, to ensure your World of Warcraft gaming experience is unaffected.