Please check this link for more information: the Beta, several startup issues were resolved by setting the Diablo III tools to run in Compatibility Mode.
After pre-ordering tonight and downloading the client to be ready for Tuesday, we ran into the same problem and thought all hope was lost. Close it, and ctrl alt delete and end the “Agent” process. Go to C/programdata/battle.net/agent and run the “Agent” executable 4. An user on the forums posted his version of the C:\Program Data\Battle. All you have to do is replace his version with your old version, and hopefully everything should work (as it did for me).” -SCH from comments - Fix #5 Additional Notes: If you get a decryption error it means you probably didn’t finish the download. decryption error might also indicate a corrupt download.
Graev has Windows Vista and could not get past the “Updating Setup Files” little window that came up. ) This one worked for me: try and find the agent application in the folder (for example C:\Documents and Settings\All Users\Application Data\battle.net\Agent). Check the folder you downloaded your files into for any that say . Run the downloader in the same directly you chose originally and it should fix the files automatically and/or finish downloading.
We know the unsupported cards aren't going to perform well and there's nothing we'll be able to do to remedy it.
Using the program Swiftshader can successfully load the game even on extremely low powered machines.
Worse is that I am unable to uninstall the desktop launcher because my computer says it is in use, even though I have exited the program. Killed all processes, restarted the computer, tried opening the launcher for wow directly, tried running the directly.