PRB: ASP.NET Applications Experience Unexpected Behavior After Upgrade

After you install the .NET Framework version 1.1 or Microsoft Visual Studio .NET 2003 on a computer that has version 1.0 of the .NET Framework installed, your existing ASP.NET version 1.0 applications may not behave as expected.

When version 1.1 of the .NET Framework is installed on a computer, the script mappings in Microsoft Internet Information Services (IIS) for ASP.NET are updated to point to the 1.1 version of the ASP.NET ISAPI filters. The path of these filters is the following:The path of the version 1.0 filters is the following:The ASP.NET ISAPI is updated automatically when you install version 1.1 of the .NET Framework, regardless of whether version 1.0 of the .NET Framework is already installed on the computer.

Version 1.1 of the .NET Framework is also installed during the Setup process for Visual Studio .NET 2003, as part of the prerequisites. Therefore, the IIS script mappings are also updated when you install Visual Studio .NET 2003.

To install version 1.1 of the .NET Framework redistributable without updating the script mappings in IIS, use the NOASPUPGRADE flag when you install Dotnetfx.exe version 1.1. To do this, follow these steps:

1. Click Start, and then click Run. In the Open text box, type cmd, and then click OK.
2. At the command prompt, locate the path of Dotnetfx.exe.
3. Type the following command to run Dotnetfx.exe, and then press ENTER:
   dotnetfx.exe /c:"install /noaspupgrade"

To download the .NET Framework redistributable package, visit the following Microsoft Web site: Note You cannot avoid updating script mappings in IIS to version 1.1 of the ASP.NET ISAPI when you install the .NET Framework 1.1 during the Visual Studio .NET 2003 Setup process.

This behavior is by design.

If you cannot run your ASP 1.0 Web application on ASP 1.1, reconfigure the ASP 1.0 application on the Web server. To do this, follow these steps:

1. Click Start, and then click Run. In the Open text box, type cmd, and then click OK.
2. At the command prompt, locate the following path:
   Windows Folder\Microsoft.NET\Framework\v1.1.4322\
3. Type the following command to remove ASP.NET 1.1 in IIS:
   aspnet_regiis -u
4. At the command prompt, locate the following path:
   Windows Folder\Microsoft.NET\Framework\v1.0.3705\
5. Type the following command to install ASP.NET 1.0 in IIS:
   aspnet_regiis -i

For additional information, click the following article number to view the article in the Microsoft Knowledge Base: For more information, visit the following Microsoft Web Site: