I think there is not a problem with your Jdk installation and neither with JBoss. The problem lies in setting the Environmetal variables. It will work 101 % with challenge. Try this. --> Open Environmetal settings in system and edit ClassPath, Path, Java_HOme, Jboss_Home. --> Make sure in class path you are pointing to C:\Program Files\Java\Jdk1.5.0_06, C:\jdk1.5.0_06\lib; C:\jboss-4.2.0.GA\server\all\lib if taken C drive as your default for example --> Now set your Path variables which should point like this : C:\Program Files\Java\jdk1.5.0_06\bin; C:\jboss-3.2.5\bin\run.jar; Now in User variables set Java_Home to your java installation dir Now in User variables set Jboss_Home to your jboss installation dir Very Important :: Open Jboss installation folder and find run.bat file open it in edit mode and make sure the following are set there: echo =============================================================================== echo . echo JBoss Bootstrap Environment echo . echo JAVA_HOME: C:\Program Files\Java\jdk1.5.0_06 echo . echo JBOSS_HOME: E:\jboss-3.2.5 echo . echo JAVA: C:\Program Files\Java\jdk1.5.0_06 echo . echo JAVA_OPTS: %JAVA_OPTS% echo . echo CLASSPATH: %JBOSS_CLASSPATH% echo . echo =============================================================================== the above can also be replaced with %Java_Home% also. and %Jboss_HOme%. Try this you will see success. Thanks wahed View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4139988#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...