So here you are, trying to set up a website in IIS that answers on a secondary IP address since your primary is already used by another service such as Windows Media Services but when you try to start the site you get an error:

“The process cannot access the file because it is being used by another process. (Exception from HRESULT: 0×80070020)

and in Event Viewer there may be these more detailed errors:

Unable to bind to the underlying transport for [::]:80. The IP Listen-Only list may contain a reference to an interface which may not exist on this machine.  The data field contains the error number.


The World Wide Web Publishing Service (WWW Service) did not register the URL prefix http://yourdomain:80:x.y.z.w/ for site 2. The site has been disabled. The data field contains the error number.

You find this odd since you have your other service set to only listen on your primary IP (are you sure?.. go check it) so the secondary IP should be available for IIS.  Then you look the error up on Google and find this KB article but for some reason creating the “ListenOnlyList” subkey  doesn’t solve this and you are still getting that error.  Yes, I had that problem until I found another way to add the ListenOnly IP.  Simply running

netsh http add iplisten ipaddress=x.x.x.x

where x.x.x.x is your secondary IP address,  try it and see if it solves your problem.


One Response to IIS 7.5 not starting web site – Error 0x80070020

  1. Steve says:

    Very frustrating and good info. It’s also relevant on IIS 7.0 as well. Here’s a KB covering your solution.