If you are a beginner why are you using the old developer release, the latest release is 4.0.1.
I don't think this would change anything, but the reason is I got this version on cd and I don't have adsl so.
I don't think this would change anything
The developer releases of JBoss 4 where previews so that developers could start to look at the new features that had been implemented for J2EE 1.4. It was not until after another developer release had been made two months later that the code was considered ready to start moving towards the production release and the release candidate releases started.
I remember at the time there were some conflicts with the JBoss 4 JMX implementation and JDK 1.5, I can't remember the details but I think the workaround involved removing some classes from the JDK. The error you have reported suggests to me that your problem is along simiar lines.
If you can not download a later version of JBoss do you have a 1.4 version of a JDK that you could use instead?
I would still recommend that you move to a production release as soon as you can, the availability of support is going to be very limited for an intermediate developer release when two production releases have been made since.
Remove jmxri.jar from \jre\lib\ext
After 3 days with headache...the solution...
My 2 cents.