Hello everyone, 

I finally found a solution (at least worked for me) for the famous error "Unable to connect to Visual Studio's Localhost Web Server" which was troubling everyone.
I encountered this error too. Tried all the options I could but finally got the way out!

Here it is:

Note: If you are running on IIS and getting this error, your computer might have been coufigured for localhost:port[some port no.]

Do this:

1. In Visual Studio IDE, go to the Website Menu and click Start Options.
   
2. From the list on the left hand side, choose Start Options.
3. Under the Server section, Choose the radio button: Use customer Server.
4. Then type in the Base URL: http://localhost/[you website name]
5. Thats it!

 Now, just run your website and this should work for you. If not, please let me know immediately!

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Thank you!