Aspnet_regiis.exe is installed in the Microsoft.NET Framework directory. If the computer is running multiple .NET Framework versions side-by-side, multiple versions of the tool might be installed. The following table lists the locations where the tool is installed for different versions of the .NET Framework.
|Version of .NET Framework||Location of Aspnet_regiis.exe file|
|.NET Framework version 1||%windir%\.NET\Framework\v1.0.3705|
|.NET Framework version 1.1||%windir%\Microsoft.NET\Framework\v1.1.4322|
|.NET Framework version 2.0, version 3.0, and version 3.5 (32-bit systems)||%windir%\Microsoft.NET\Framework\v2.0.50727|
|.NET Framework version 2.0, version 3.0, and version 3.5 (64-bit systems)||%windir%\Microsoft.NET\Framework64\v2.0.50727|
|.NET Framework version 4 (32-bit systems)||%windir%\Microsoft.NET\Framework\v4.0.30319|
|.NET Framework version 4 (64-bit systems)||%windir%\Microsoft.NET\Framework64\v4.0.30319|
Directories for the .NET Framework versions 3.0 and 3.5 do not have a copy of the tool. For more information, see the entry How to set an IIS Application or AppPool to use ASP.NET 3.5 rather than 2.0 on Scott Hanselman’s blog.