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.
Okay. I finally got to the bottom of this. You need to jump through some hoops to get the PUT and DELETE verbs working correctly with IIS8. In fact if you install the release candidate of VS 2012 and create a new WEB API project you'll find that the sample PUT and DELETE methods return 404 errors out of the box.
To use the PUT and DELETE verbs with the Web API you need to edit %userprofile%\documents\iisexpress\config\applicationhost.config and add the verbs to the ExtensionlessUrl handler as follows:
Change this line:
<add name="ExtensionlessUrl-Integrated-4.0" path="*." verb="GET,HEAD,POST,DEBUG" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" />
to:
<add name="ExtensionlessUrl-Integrated-4.0" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" />
In addition to the above you should ensure WebDAV is not interfering with your requests. This can be done by commenting out the following lines from applicationhost.config.
<add name="WebDAVModule" image="%IIS_BIN%\webdav.dll" />
<add name="WebDAVModule" />
<add name="WebDAV" path="*" verb="PROPFIND,PROPPATCH,MKCOL,PUT,COPY,DELETE,MOVE,LOCK,UNLOCK" modules="WebDAVModule" resourceType="Unspecified" requireAccess="None" />
Also be aware that the default Web API convention is that your method name should be the same as the invoked HTTP verb. For example if you're sending an HTTP delete request your method, by default, should be named Delete.
Best Answer
If your website project was opened via IIS, it should debug the IIS process automatically. If your site exists in IIS currently, you should be able to find it via File -> Open -> Web Site.
If you opened an IIS Express based website project (or via the file system, which uses IIS Express by default), then run the site through IIS, VS doesn't know that the site is running in IIS.