This seems to be a very common problem with many of us..
While trying to restart IIS you suddenly start to get this message “Unexpected error 0×8ffe2740 occurred.” or your Apache on Windows would fail to start..
In most probable cases the culprit would be Skpe, so check to see if Skype is running and turn it off.
Try starting your IIS or Apache hopefully it should start now.. and after you have your IIS or Apache running then start Skype.
The reason for this is.. Skype by default looks to see if port 80 is free and if it is.. it will use port 80 to run.. and since both IIS and Apache also look for port 80 they fail if Skype has taken it up.
On the contorary if Port 80 is being used by either IIS or Apache, Skype will conveniently use another port.
