Further to comments on my previous post on this topic, I realised my HttpModule which gives a user a friendly error message if they upload a file which is too big only dealt with half of the problem. The maximum size a request can be is specified in the machine.config and web.config in the maximumRequestLength attribute on the httpRuntime element; if a user uploads a file which is larger than that, the part of the HttpModule which checks the request size is by-passed, and the user gets a not-ver