When "World of Warcraft" isn't functioning properly, one of the earliest troubleshooting steps you can take is to clear the game's data cache. The cache is designed to shorten load times and CPU cycles by storing some of the data there for quick access. A corrupted cache can cause the game to malfunction or perform poorly, meaning its deletion is an important step to repairing the problem. Don't worry; deleting the cache won't damage your game and the cache will be rebuilt on your next start-up.
Close out "World of Warcraft" and any other Blizzard games, and close out the launcher client. These programs need to be closed so that the cache can actually be deleted and rebuilt.
Press "Ctrl-Shift-Esc" to launch the Task Manager. Windows 8 users can also press "Windows-X" and select Task Manager from the power user menu.
Select the Processes tab and find "agent.exe." Click the "End Process" button to close out the process. This completely closes out the launcher and Blizzard agent, so that it can't interfere with or be inadvertently damaged by deleting the cache.
Press "Windows-R" to open the Run dialog and enter the following path into the field, without quotes:
This is where Windows stores cache data and other similar information for various programs, including Blizzard games like "World of Warcraft."
Find the "Blizzard Entertainment" folder and delete it. This folder contains the cache data for all Blizzard games currently installed on your computer. If you only want to clear the WoW cache, you can go into the folder and delete the "World of Warcraft" folder instead.
Run the launcher client and start up "World of Warcraft." The game will build a new cache, which should fix any issues you were experiencing before. If the problem persists, contact Blizzard technical support for further diagnostics and troubleshooting.
Tips & Warnings
- As well as being useful for technical troubleshooting, clearing the cache can be beneficial for certain add-ons. Add-ons designed to locate rare enemies like SilverDragon or NPC Scan note monsters already found in the cache and don't pop up when they spawn, even if that happens to be an enemy you're hunting for. Clearing out the cache cleans the slate so that the add-on can pop-up properly when the monster spawns.
- Periodically cleaning out the cache is a good habit to develop, as it reduces the likelihood of cache errors, corruption or out-of-date information interfering with your game's performance. Making it part of your usual computer maintenance routine, along with running anti-virus scans and other security and performance maintenance, is a good way to keep track.
- Your first load after cleaning your cache will be a bit slower than usual -- this is normal. The cache has to be rebuilt, which means the data has to be reloaded into it, which takes a little more time.
- Although it's okay to delete your WoW cache, don't delete any other data unless specifically instructed to by a Blizzard tech support staff member. Deleting the wrong files can have serious implications for your game's performance and functionality -- especially don't delete .MPQ files, which are WoW asset databases and vital to the game's operation.