How to solve HTTP 500.12 Handler "PageHandlerFactory-Integrated" has a bad module "ManagedPipelineHandler" in its module list

Your ASP.NET may not be configured properly for IIS if you see this message:

HTTP Error 500.21 - Internal Server Error
Handler "PageHandlerFactory-Integrated" has a bad module "ManagedPipelineHandler" in its module list

Resolution

1. Navigate to C:\Windows\Microsoft.NET\
2. Open a terminal here.
3. Type aspnet_regiis.exe -i and then enter.
4. You should see the following if it finished correctly:
1. Start installing ASP.NET
2. ..........
3. Finished installing ASP.NET
5. Restart the IIS server.

Troubleshooting

Check the path to make sure it actually exists.