An update to the Blizzard launcher and associated tools this afternoon has been causing problems for folks running various versions of Windows. The bug has a chance of occurring when you get stuck at a "Waiting for files to close..." dialog box when updating. Blizzard support staff was quick to announce a fix, which is pretty easy to do.

To solve this, go into the task manager (you can get to that by right-clicking on the bottom taskbar on your screen and selecting "Start Task Manager," or by pressing the control, shift and escape keys all at once) and end any and all of the following processes in the "Processes" tab:
  • WoW.exe
  • Launcher.exe
  • BackgroundDownloader.exe
  • Repair.exe
  • WowError.exe
After you make sure none of the above processes are running, you'll be able to move forward with the update and get WoW working again.

The full Blizzard statement after the break.


Waiting for files to close...
A Tools patch was released this afternoon, which includes new versions of:

Blizzard Updater
BackgroundDownloader
Launcher

If you are getting the message "Waiting for Files to Close...", please try using Task Manager to End one of the Processes, as described below.

This is from our sticky, 3.3.x Patch common issues

http://forums.worldofwarcraft.com/thread.html?topicId=18971780462&sid=1#2

6. The patcher is waiting for files to close.

This issue happens if one or more of your game files are open. Windows locks it so you can't overwrite it. You need to close them first before the patcher can continue. Try hitting Control+Alt+Delete < or Ctrl + Shift + Esc > on your computer. Make sure none of these are running in the Processes tab:

WoW.exe
Launcher.exe
BackgroundDownloader.exe
Repair.exe
WowError.exe

If any of those are running, try ending the task. The patch should continue afterward.
____________________________________________________________________

Oftentimes, a Selective Startup can help too:

Hit the Windows Key + R, and type:

msconfig

Hit Enter or OK.

In the General tab:

1. Choose Selective Startup
2. Disable (uncheck) Load Startup Items
3. Click OK and Reboot


This article was originally published on WoW Insider.