The "--jaxp=crimson" option does not work with a clean instalation of JBoss 4. And it should, at least according this:

>run -h
...
-j, --jaxp=<type> Set the JAXP impl type (ie. crimson)
...

But it does not:

>run --jaxp=crimson
...
12:19:49,343 ERROR [MainDeployer] Could not initialise deployment: file:/C:/Common/jboss-4.0.1sp1/server/default/conf/jboss-service.xml
javax.xml.parsers.FactoryConfigurationError: Provider org.apache.crimson.jaxp.DocumentBuilderFactoryImpl not found
...

Apparently this is caused by the missing "crimson.jar" file:

File: system\src\main\org\jboss\Main.java
Lines: 370-375

if (arg.equals("crimson"))

{ domFactoryType = "org.apache.crimson.jaxp.DocumentBuilderFactoryImpl"; saxFactoryType = "org.apache.crimson.jaxp.SAXParserFactoryImpl"; jaxpLibs = "crimson.jar"; }

However I'm new to JBoss so I'm not 100% sure that this is causing the problem.