If you plan to use the SAP Enterprise Portal adapter with the Sun Application Server on a Windows machine, you must add SAP JCo RFC dlls to the Sun Application Server /lib directory or an error will result.
For SAP JCo 2.1.8: Add the sapjcorfc.dll and the librfc32.dll files to the Sun-app-server-install-dir/lib directory and restart the server.
For SAP JCo 3.0.x: Add the sapjco3.dll file to the Sun-app-server-install-dir/lib directory and restart the server.