If you install Visual Studio 2010 SP1 and then you find that IIS will not start, you may have a port conflict issue.  SP1 includes a new service, the Web Deployment Agent Service.  This new service runs on port 80, the same default port that IIS uses for HTTP traffic.  If the Web Deployment Agent Service is running, IIS will not start if you are using port 80 in IIS.  On option is to modify the web deployment agent service.  For me, I stopped and disabled since I do not plan to use.  You may be able to change the port is uses by default.  Additional info can be found at the link below

http://superuser.com/questions/282519/change-the-port-of-iis-7-5-express