Thank you for your post, and I apologize for the late reply.
It sounds like FileMaker Server 8 is still running on the original machine. Close the databases and the server on the original machine. Now, if FileMaker Server 8 was set up properly on the new machine, make sure it is running. You should then be able to see the files when a client selects "Open Remote" from the File menu.
If you are still having difficulty, please let me know.