eclipse configuration

i have downloaded jboss 4.2.0 ga and kept it in the same named folder
now i have set the build path to this folder
but when i start my new server it gives java lang nullpointerexception ?

i tried many times but it doesnt go ?
what could be the issue help required..

You raised this a san eclipse question, so I moved this to our IDE forum.

duplicate. Please one post per question.