Those of you using Windows XP may be experiencing technical issues with the Battle.net® Desktop App since its most recent update which prevents you from launching Blizzard games from the client. Please know that we're aware of the problems and working to get them resolved as soon as possible.
In the meantime, to temporarily resolve the issues, you'll need to manually uninstall all Battle.net related files including the Battle.net Desktop App. Here are some step-by-step instructions:
1. Show hidden files and folders.
2. Using Windows Explorer, delete the following folders:C:\Program Files\Battle.netC:\Documents and Settings\All Users\Application Data\Battle.net3. Choose the appropriate option for the launcher you use:
Battle.net Desktop Application & Hearthstone users: Use the updated Battle.net or Hearthstone installer on the Battle.net Games Management page to reinstall Battle.net application and related files.Classic launcher users: Launch the game using the normal shortcut to download the updated Battle.net/Agent files.
For additional assistance with this issue, please refer to our Technical Support forum.