Step 1: Central Administration -> General Settings -> Edit “Maximum Upload Size”:
Step 2: Edit web.config under C:\inetpub\wwwroot\wss\VirtualDirectories\[YourWeb]
<httpRuntime executionTimeout=”999999″ maxRequestLength=”51200″ />
Step 3: Edit web.config under C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\12\TEMPLATE\LAYOUTS
<location path=”upload.aspx”>
<system.web>
<httpRuntime executionTimeout=”999999″ maxRequestLength=”2097151″ />
</system.web>
</location>
Step 4: Add this lines to web.config under C:\inetpub\wwwroot\wss\VirtualDirectories\[YourWeb] (If you get 404 error after file upload)
<system.webServer>
<security>
<requestFiltering>
<requestLimits maxAllowedContentLength=”52428800″/>
</requestFiltering>
</security>
