When I try to upload larger files through File Manger or other modules I get the error below.  This includes a file that is 44 MB.

HTTP Error 404.13 - Not Found
The request filtering module is configured to deny a request that exceeds the request content length.

I have changed my web.config to:
<httpRuntime useFullyQualifiedRedirectUrl="true" maxRequestLength="512000" requestLengthDiskThreshold="512000" executionTimeout="3600"/>

I am running DNN version: 04.09.02 using IIS7 on Windows 2008. 

Any ideas what else I need to change to allow large file uploads? 

Thanks.

Its been a while, but I think you want to lookup details on the following path/settings in web.config.

<system.webServer>
<security>
<requestFiltering>
<requestLimits maxAllowedContentLength>

While you are at it, make sure you do the math and pay attention to your executionTimeout.  I had mine right for my environment and was uploading 300+ MB files.  But I was on cable.  My client was on a truly crap, overburdened DSL at an office with an Exchange server and 15+ workstations.  Just to get it so they could survive the upload time of a 100 MB file I had to get the executionTimeout to 3 hours - but it did work.  Best of luck, cheers - Jeremy