In Visual Studio 2005 you may encounter this error when starting an ASP.NET 2.0 debugging session. Particularly you might encounter it if you are using the ASP.NET development server local web server running a local filesystem web site project.
Unable to attach. The binding handle is invalid.
Do you want to continue anyway?
Yes / No
To fix this error, go to Start Menu --> Administrative Tools --> Services
Select the Terminal Services service and make sure it is started.
I got this error because in my machine the Terminal services was disabled.