No .ASPX extension (Extensionless page)

To achieve the goal as mentioned in title, you will need to set the IIS as follow:

1. Open IIS Manager

2. Go to the website instance you want to configure, right click and click property.

3. Click Home Directory

4. Click Configuration

5. Under Wildcard Applications Maps, add the following DLL

C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\aspnet_isapi.dll

6. Hit OK

Untick "verify that file exists" if you want a hybrid.