There are several resources available to you to help resolve problems with installing or running the game software. Technical Support Forums
The first stop for all client installation and troubleshooting questions should be the technical support forums hosted at atitd.org. Most frequently asked questions can be answered simply by reviewing the contents of the forum.
The Windows technical support forum can be found here.
The Linux technical support forum can be found here.
The MacOSX technical support forum can be found here.
Techincal Support on IRC
If the forums don't quite have the answer you are looking for your next stop should be the Internet Relay Chat service sorcery.net. Using any IRC client, connect to irc.sorcery.net. Once there join channel #atitd for Windows support or #atitd-unix for Linux or MacOSX support.
Technical Support by eMail
If you are unfamiliar with IRC, or the above resources do not contain the information you need to resolve your problem, you can get further support by emailing email@example.com. To recieve help you must provide a comprehensive description of your problem, including what platform you are attempting to run the client on, and the exact text of any errors you encounter. Please allow anywhere from 8 to 24 hours for a response to your problem (the time it takes to respond greatly depends on if it is daytime in the US). If you do not recieve a reply within 24 hours please re-submit your support request, as emails sometimes get lost among the flood of spam we receive.