Admin console fails to launch after updating to Java 6 (24) on a Windows7 client
The Java 6 (24) update is not compatible with Admin console. You can read about it at http://thefmkb.com/7937 . If you have already installed Java 6, you will need uninstall it, reboot, and then go to http://java.sun.com/products/archive/j2se/6u23/index.html and download the JRE (Java Runtime Environment) file.
For More Information see: Unable to launch the application : FileMaker Server 11 Admin Console
This is one of many acknowledged bugs that can be found in the Known Bug List here in the Report an Issue section of the forum.
It can also be downloaded as a database file from: http://www.4shared.com/file/8orL8apk/FMP_Bugs.html