I get error message \"Unable to start debugging on the web server\" in Visual Studio 2010. I clicked the Help button and followed the related suggestions without success.
Your solution file in visual studio is broken. It's a known issue when converting from a file-system website to an IIS website, and it has been carried over from 2008 to 2010. Not sure of the location for the bug report on ms's kb site, though.
Remove the website from the solution file (right click the project name, click "remove"). Then right click the solution name, click "add existing web site". When the dialog to add a web site comes up, choose "from IIS" in the left-hand pane. Navigate to your application in IIS, select "use secure sockets layer" if necessary, and click "finish" (or whatever that button is labeled).
this will permanently fix the issue.