IIS7 problem on 2010 exchange server

Hi
A 2010 exchange on was installed on 2008 server by somebody else in one of our branch offices. We have Exchange 2003 in HQ and managed to set up emails routing between both exchange servers and users in the branch office are using new, local exchange fine.
The problem I have is with IIS7 on the new exchange. It was never working (there is a question mark over Default Web Site, can’t get OWA etc.). I tried to fiddle with it a bit but possibly made it worse. When I try to access exchange or any other .html file (I’ve created for testing) using http://localhost/…… I just get a blank page.
It’s probably something to the handler but I don’t know much about IIS and have no idea what to do next.
Any help much appreciated