I was getting some 404 errors while using the FileUpload control. I tested it out on my local machine and using
<system.web>
<httpRuntime maxRequestLength="256000"/> <!-- request length is in kilobytes -->
</system.web>
worked fine. But once I moved it onto IIS7 everything started freaking out. Turns out IIS7 look for a different setting:
<system.webServer>
<security>
<requestFiltering><requestLimits maxAllowedContentLength="262144000" /></requestFiltering> <!-- maxAllowedContentLength is in bytes. Defaults to 30,000,000 -->
</security>
</system.webServer>
My searches really only directed me to modifying the system.web, so hopefully this will help someone out.