Error 0x80070020 when you try to start a Web ...

At times you may notice that one or more Web sites are not started in IIS 7.0. If you try to manually start the Web site, it may fail with the following error message:

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

This issue may occur if TCP port 80 and/or 443 is grabbed by a different service.

Run the following command from a command prompt to find the PID of the process which is using TCP port 80 and/or 443.

               netstat -aon | find ":80"

               netstat -aon | find ":443"

You will see an output similar to the following. Remember the actual PID will vary from case to case.

               TCP    0.0.0.0:80             0.0.0.0:0              LISTENING       3604

               TCP    0.0.0.0:443           0.0.0.0:0              LISTENING       3320

Now using Task Manager you can easily find out to which process the above PID belongs and take appropriate action.