He must have installed 2005 "over" 2003 in the same directory? It installs by default to a different separate directory. Even the framework can co-exist side by side. It is a drain on your system if your system is not very fast and you install multiple IDEs. I have 2003 and VS 6 side by side and it slows down my system just a bit but then I am running a P4 2.8 high performance system.