An Application Pool that only serves static files with all features installed will have a footprint of 3 MB private bytes, 5 MB page file. (This is larger than IIS 6.0). Windows Server 2008 handles multiple application pools better than WS03. When ASP.NET requests are made we pre-load a small amount of the CLR during startup (~100kb) . The preload is configurable by a property on the ApplicationPool. It is called managedRuntimeVersion. The rest of the CLR (~8mb) will be loaded on the first ASPX request.