This might be considered an exploit of the way that the client is reporting Error 37 to indicate that servers are too busy.
If you are running a Windows version later than 7 it's recommended to install the game outside the "Program Files" directory.
Something like "C:\Games\Diablo II", for example, should work fine.
The game features elements of the hack and slash, action RPG and dungeon crawl genres.
For more details about Diablo 3, you can check out the official home page or the Wikipedia article.
For example, the game can be run on integrated graphics as low powered as the Intel G41, albeit at extremely low frame rate. This means that no license is attached to the account, a problem with many users in Asia. This message means that the login servers are at full capacity.