I'm having some problems I hope someone can shed some light on. Contrary to the Winhost message of "By default the asp.net user has full permissions to your site", I simply cannot get the following code to execute on my site: var dir = Server.MapPath("~/MyFolder/NewPath"); Directory.CreateDirectory(dir); This always returns an UnauthorizedAccessException and any other attempt to write to the file system (i.e. creating a text file), results in an error. I've just tried creating a brand new empty ASP.NET web app with all the defaults and the same thing happens. Personally, I believe the identity the app is running under simply doesn't have write access to the file system. Winhost have now said it's an app configuration error and that I should seek support from the programming community. There's a question on Stack Overflow under Possible causes for Directory.CreateDirectory throwing UnauthorizedAccessException on shared host. Would anyone here have any thoughts on possible causes? Likewise, can anyone here actually write files or directories to their Winhost site?