Unable To Launch Web Server Unable To Launch Web Server asp.net asp.net

Unable To Launch Web Server


I was having similar problem in visual studio 2012:

ERROR:" Unable to launch IIS Express web server.

Failed to register URL http://localhost:1030/ for site "MySite" application "/". Error Description: The process cannot use file because it is being used by another process. (0x85968574) "

REASON : Actually this port numbers are dynamically generated at runtime. It dosent guranteed to be available. If it is acquires by some other process project wont run. So we need to try at another port.

SOLUTION : There are various solution i found on internet but problem remains unsolved. Finally I tried following solution :

  1. Right click on project in solution Explorer -> Properties
  2. Click on to Web (On LHS).
  3. Look at local IIS Web Server (Which would be radio btn selected by default).
  4. Change port no of project Urle.g : http://localhost:1030/ to http://localhost:45896/ (Possibly Higher than 1024)
  5. Save changes and run application.

This makes changes in IIS config files and wherever needed automatically so we don't need to change any code explicitly. That's work for me hope will work for You too.


From the MSDN library

Visual Studio cannot guarantee that the port you specify will be available when you run your file-system Web site. If the port is in use when you run a page, Visual Studio displays an error message.

To change the port used by IIS Express to run your program you should follow the procedure outlined by this article on MSDN

How to: Specify a Port for the Development Server

In short, we need to edit the file %systemdrive%:\Users\<username>\Documents\IISExpress\config and change the binding information found in this file and change other configurations for the IIS Express.

As a consequence of this not so simple way to fix the problem, I recommend to close the application that tries to use that port access on you dev computer. Look for specific tools like TCPView from Microsoft that could help to spot the application that grabbed your port. Often it is only the browser


Run "netstat -b" from the command prompt to see what application is using port 4012. If you kill the process IIS Express will be able to launch using port 4012.