If you are using FileUp to perform uploads in ASP.NET on a machine with IIS 7 (Windows Vista, Windows Server 2008) or IIS 7.5 (Windows 7, Windows Sever 2008 R2), your FileUp application must be assigned to a application pool that is set to Classic pipeline mode.

Most installations of IIS 7.x on 32-bit machines come with a Classic .NET AppPool, but this article will cover how to create one from scratch.

For instuctions on how to create the appropriate application pools on a 64-bit OS, please refer to: How to run FileUp on a 64-bit Windows Operating System

NOTE:This is not required for applications in classic ASP or ASP.NET applications that are performing downloads only.

Creating a Classic .NET Application Pool

1. Go to Internet Information Services (IIS)
2. Right-click Application Pools from the left pane and select "Add Application Pool"
3. In the Add Application Pool window, enter a name for the application pool, for example "FileUp Classic .NET AppPool"
4. Select the version of ASP.NET your application pool should have. The image below shows .NET 2.0, but if you are using ASP.NET 4.0, you should set the .NET version to 4.0 instead.
5. Set the managed pipeline mode to Classic
6. When you are done, the application pool settings should look like this:
   
   
   
7. Click OK.

Setting your Application to use the Application Pool

1. In IIS, go to the virtual directory for your application and right click on your application.
2. Go to Manage Application > Advanced Settings.
3. In Advanced Settings, under General select Application Pool and click the button that appears when selected. This will open the Select Application Pool window.
4. Change the Application Pool setting from DefaultAppPool to Classic .NET AppPool from the drop-down.
   
   
   
   
5. Click OK.

Your FileUp application must be assigned to this application pool.

Please refer to HOW-TO: Add FileUp to an ASP.NET application for instructions on setting up a new application.