Repair IIS Mappings to .NET

Provided by Molly Pell, Senior Systems Analyst

If you install IIS AFTER installing the .NET Framework, IIS will not be properly mapped to ASP.NET. This may cause ASP.NET web applications or services to give you an error such as:

Visual Studio .NET has detected that the specified Web server is not running ASP.NET version 1.1. You will be unable to run ASP.NET Web applications or services.

To resolve this issue, you must repair IIS mappings to ASP.NET. To accomplish this, you can either uninstall and reinstall the .NET Framework, or follow these steps:

1. Open the Windows command prompt console window:
   • From the Windows Start menu, select Run.
   • Type CMD and click OK.
2. At the command prompt, type:
   <WinDir> \Microsoft.NET\Framework\ <Ver>\aspnet_regiis.exe -i
   Where <WinDir> is the directory of your Windows folder (e.g. C:\WINDOWS) and <Ver> is the actual version number of the .NET Framework (e.g. v1.1.4322).
3. Press Enter to run the executable. When it completes, close the command prompt console window.
4. Register aspnet_isapi.dll:
   • From the Windows Start menu, select Run.
   • Type the following in the Open field, and click OK:
     regsvr32 "<WinDir>\Microsoft.NET\Framework\<Ver>\aspnet_isapi.dll"

After aspnet_isapi.dll has been successfully registered, the IIS mappings to ASP.NET are repaired, and you will no longer encounter the error.