Unable to start debugging on the web server. An unexpected DCOM error occurred while trying to automatically attach to the remote web server. Try manually attaching to the remote web server using the 'Attach To Process' dialog.

This is what I did

1>Click on website in IIS 7.5. On the right side of the screen under Actions, click on "Basic settings". That opens up a pop up as shown below.

2>Click Connect as in the pop up window shown above.

3>Select Application user

4>Open IIS manager and navigate to Authentication. Enable Windows Authentication.