Follow these steps to open an Iron Speed Designer-generated application in Microsoft Visual Studio .NET 2005:
Step 1: In Microsoft Visual Studio .NET, select File, Open, Web Site...

Step 2: Select an application folder and click Open button.

Working with Microsoft Visual Studio .NET
Opening a Generated Application in Visual Studio .NET
Custom Controls Generated by Iron Speed Designer
Enabling and Disabling Strict Compilation Mode
Compiling Applications in Debug Mode
Editing ASPX Pages in Visual Studio .NET