ASP.NET : HTTP Error 404.3 – Not Found

How to solve the error ASP.NET : HTTP Error 404.3 – Not Found

I’m starting the first post by giving a solution to an issue that I faced when installing Visual Studio and IIS 7 in my new laptop, and trying to run my ASP.net web application.

Error Details :  HTTP Error 404.3 – Not Found
The page you are requesting cannot be served because of the extension configuration. If the page is a script, add a handler. If the file should be downloaded, add a MIME map.
This error happens when you install IIS after Visual studio, so you have to configure ASP.net with IIS.

Solution: to solve this issue, you may use Aspnet_regiis.exe (ASP.net IIS registration tool, more info here), to do this, follow these steps:

1. find  the path where aspnet_regiis.exe is situated, it should be situdated here :
   C:\Windows\Microsoft.NET\Framework\v4.0.30319
2. run cmd as an administrator and  run aspnet_regiis.exe by typing this command line :
   C:\Windows\Microsoft.NET\Framework\v4.0.30319\aspnet_regiis -i
   (the option -i installs the current version of ASP.NET and configure IIS to use it)
3. Run your web application again, that should work properly

Hope that was helpful.