"Unexpected error 0x8ffe2740 occurred" is not a particularly helpful error message. It just means IIS can't start a website because port 80 is already in use.
MS KB article 816944 has more info.
A likely suspect is Skype, since it will use port 80 if it's free. This is a tricky one, since IIS might work fine most of the time since it starts up before Skype, but if you stop and restart IIS Skype sees port 80 is free and snakes it. 08ffe2740 for you!
IIS-Resources has the answer but not enough Google Juice. Here's the fix:
Skype File-> Options -> Connection
Uncheck Use Port 80 as an alternative for incoming connections.
Restart default website.