There are several background process that prevents the Compass from being completely deleted. We can try around with this work around.
1) Stop the Compass Server, robot, import agents, etc.
2) Go to the Task Manager and stop the three processes that start with "db_": db_deadlock.exe, db_checkpoint.exe, and db_logclean.exe
3) Remove the server through the administration interface as usual
Thanks,
Raj_indts
Developer Technical Support
Sun Microsystems
http://www.sun.com/developers/support