Unable to launch the IIS Express Web Server - Dual instances?


[.NET MVC, VS 2013, Windows 10]

Error: Unable to launch the IIS Express Web Server. Failed to Register URL "http://localhost:61493/" for site "SiteName(1)" application "/". The process cannot access the file becuase it is already being used by another process. (0x80070020)

There are some other SO Questions about this, but my problem appears to be different. Notice the (1) after the site name in the error. It appears that when I run the app with Visual Studio, there are somehow two instances of the app running that cause it to want to fire up two processes running on port 61493, and they are fighting with each other. When I used a netstat -ao | findstr 61493 command, the command just hangs. When I used netstat -b, it showed lots of processes, but none running on 61493.

I have tried:

  • Changing my port number
  • Clearing my browser history
  • Clearing sites from applicationhost.config
  • Ending IIS processes via Task Manager

The only thing that works is restarting my computer, then the problem shows up again after a day or two.

asked on Stack Overflow Jul 22, 2016 by Justin Haight

1 Answer


I use windows 10 and vs2013 too this usually happens when I debug run my project multiple times without properly ending the current one. Exiting the IIS Express under the system tray icons always resolves the issue for me.

answered on Stack Overflow Jul 23, 2016 by super-user

User contributions licensed under CC BY-SA 3.0