Visual-studio – Unable to launch the IIS Express Web server

Right click on solution --> Properties

Look under Common Properties --> Startup Project

Select multiple startup projects

select Start action on the projects you need to debug.

This is what worked for me (Updated for VS 2013, see revision history for 2010, for VS 2015 see this: https://stackoverflow.com/a/32744234/218971):

1. Right-click your Web Application Project ▶ Properties ▶ Web, then configure the Servers section as follows:

   • Select IIS Express ▼ from the drop down
   • Project Url: http://localhost
   • Override application root URL: http://dev.example.com
   • Click Create Virtual Directory (if you get an error here you may need to disable IIS 5/6/7/8, change IIS's Default Site to anything but port :80, make sure Skype isn't using port 80, etc.)

2. Optionally: Set the Start URL to http://dev.example.com

3. Open %USERPROFILE%\My Documents\IISExpress\config\applicationhost.config (Windows XP, Vista, and 7) and edit the site definition in the <sites> config block to be along the lines of the following:

   <site name="DevExample" id="997005936">
       <application path="/" applicationPool="Clr2IntegratedAppPool">
           <virtualDirectory
               path="/"
               physicalPath="C:\path\to\application\root" />
       </application>
       <bindings>
           <binding
               protocol="http"
               bindingInformation=":80:dev.example.com" />
       </bindings>
       <applicationDefaults applicationPool="Clr2IntegratedAppPool" />
   </site>
   

4. If running MVC: make sure the applicationPool is set to one of the "Integrated" options (like "Clr2IntegratedAppPool").

5. Open your hosts file and add the line 127.0.0.1 dev.example.com.

6. ► Start your application!

Some great advice from the comments:

• You may need to run Visual Studio as Administrator.
• If you want to make other devs see your IIS run netsh http add urlacl url=http://dev.example.com:80/ user=everyone
• If you want the site to resolve for all hosts set bindingInformation="*:80:". Use any port you want, 80 is just convenient. To resolve all hosts you'll need to run Visual Studio as an administrator