If you have any anti-virus or malware software installed, try turniong it off in case it is the cause of the block.
Also you should check the web config tool settings (in same folder) and make sur ethe paths are correct. If you have had multiple versions of CF installed, it may be trying to conect to previous version.
also try the suggestion in this article: http://www.michaels.me.uk/post.cfm/cfmx7-installation-and-web-server-c onfiguration-tool-fails-with-jndi-ports-blocked
JRUN service is the ColdFusion application server, you will see JRUN running if you bring up the task manager.
I also noticed that you mentioned "ColdFusion 4", was this a typo ?
