Today I installed VS2010 SP1 Beta, and IIS 7 Express, as I currently have IIS5 on my local development machine and thought I\'d try IIS Express out.
I have gone into the
I had a similar problem. It seems that if IIS Express is already running a particular site and then you try to run a project that uses that site through Visual Studio it isn't able to attach the debugger. The solution was to close any running instances of IIS Express and WebMatrix and then try running the site through Visual Studio (F5).
I recommend installing WebMatrix as it's the simplest way of managing the sites and port numbers that you are using.