IIS start: Unexpected error 0x8ffe2740 occurred

If you got the above error when trying to start the IIS services, then the most probable reason is, there is another application which is utilising the port that conflict with IIS on port 80. One way to resolve this is by changing their port, either one.

This error striked my PC and the application that uses the conflicting port was skype. Upon after quiting the program and triggering the start on IIS, it was then successfully executed.