Here you can find the minimum requirements for using the client:

Flash Player 9.0 (or higher)
Internet Explorer 6+ or Mozilla Firefox 3+
CPU: 2000 MHz
Graphic card: 64 MB
2 GB main storage
Sound card
Desktop resolution 1024x768 Pixels

Note: We cannot guarantee that you can play via the client with Linux and MAC.

In case of problems, please contact support with an exact description of the issue. If possible, please also attach a screenshot.