Remote Web Access Service Doesn't Work

I am able to use remote desktop access to log in on whs2011, but I can't use remote web access (http://localhost) to connect to whs.  I checked the IIS service and notice it has stoped.  And I tried to start the service and here is the error message that I got: "can not start the website, the process can not start because it is being used by another process (exception HRESULT: 0 * 80070020).

Event ID 1004

Event source: IIS-W3SVC

Local ID 3081.

for your troubleshooting: i've manually set up the router as follow:

reserved an IP address for the whs.

set up port fowarding (port 80, 443 and 4125) to wsh's IP address.

Please anybody helps me out. Thanks a lot for your help.