Go to the JBoss SourceForge site for free documentation. The error you report is a problem with the JVM, not with JBoss. As reported, Hotspot had some issue with executing the byte code. Moist likely you should upgrade your JDK/JVM.
You can also browse through http://www.amitysolutions.com.au/downloads/response_tester.pdf as it has some general information on setting up JBoss and dealing with some operational matters. As you will see, there is not much in the way of installing JBoss.
I unpacked and ran the server on Win2k without problem. The run.bat script will startup services in @ 20 secs and I was able to connect to htt://localhost:8080/web-console
Thank you for your help!!