Sharepoint debugging isn’t fully automated. So you should really know how to debug and diagnose your assemblies in any given situation. 1. Attaching to the process It only applies to a debugging environnement. This is the one that everybody knows (or should at least). You deploy your DLL in the GAC, restart your application pool, access your sharepoint web application in order to load the application pool and the DLL and then attach to the right w3wp.