Uploading a large file: security validation has timed out MOSS2007 with Windows 2008

I am trying to allow the upload of large files (e.g. 150 MB) into a SharePoint 2007 document library. I thought I had switched on all the correct settings, but I still receive an error message: "The security validation for this page has timed out.". This generally happens after about 8 minutes.

Here's what I have done so far:

1. Within SharePoint Central Admin > Application Management > Web Application General Settings I have set the Maximum Upload Size to 300MB and the Web Page Security Validation to 120 minutes.
   
2. The web.config file in C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\12\TEMPLATE\LAYOUTS is set to:
   <location path="upload.aspx"><system.web><httpRuntime executionTimeout="999999" maxRequestLength="2097151" /></system.web></location>
   
3. The web.config file in C:\inetpub\wwwroot\wss\VirtualDirectories\80 is set to:
   <httpRuntime executionTimeout="999999" maxRequestLength="512000" />
   
4. Also, I have added the following to the web.config file in C:\inetpub\wwwroot\wss\VirtualDirectories\80:
   <system.webServer><security><requestFiltering><requestLimits maxAllowedContentLength="524288000" /></requestFiltering></security></system.webServer>

This will work for Document Libraries.

If you want to attach large files to List then you need to change the following things

when ur uploading file into library it will redirect to upload.aspx page; coming to list its not redirecting to upload.aspx page. It will be in Editform.aspx page

 so try to add the code in 12 hive web.config file as

<location path="editform.aspx"> 

<system.web> 

<httpRuntime executionTimeout="999999" maxRequestLength="2097151" /> 

</system.web> 

</location>