The process cannot access the file because it is being used by another process. (Exception from HRESULT: 0x80070020) – IIS 7 – Internet Information Service

In IIS7 I was trying to start my Default Web Site and was getting the following error screen.

A quick Google search turned up the following Microsoft Support Topic. Ok. Lets take a look at netstat and see what might be causing problems. Open a command prompt ([Windows Key + R] and enter cmd) and enter the command. After running netstat -ano, I noticed that there was indeed another process (with a process id of 796) accessing port 80. (You can enter netstat /? to see what the –ano flags are doing.)

The offending process that is using port 80 has a process id of 796. Now, how to find out what that process 796 is?
Using the tasklist command will show a list of all processes running in windows. You can use the /fi flags to filter the results. In this case I’m using a filter that will only show processes with a PID that equals 796. tasklist /fi “PID eq 796”

The process with process id is Skype. Makes sense that it would be using port 80. I promptly closed down Skype and was then able to start my Default Web Site in IIS Manager. Hope this helps someone.