Error starting IIS Express Web Server - Error 0x80070020

Question

After leaving Visual Studio one night in mode debug stopped on a line, I could no longer run the web application locally because of an error in the IIS Express.
I tried to stop the IIS Express and reopen Visual Studio, but did not solve.

Answer 1

In accordance with that post of a blog:

The code error 0x80070020 means ERROR_SHARING_VIOLATION, that in the case of IIS Express (or IIS) means that the door IIS is trying to listen is being used by another process.

To find out which application is using the port, just run the command netstat in the cmd with the following syntax: netstat -ao | findstr número_da_porta_que_está_pesquisando

The parameter a is responsible for displaying all connections and doors heard.
The parameter o is responsible for displaying the process ID associated with the connection.

Running the above command:

C:\Users\Daniel>netstat -ao | findstr 49286
TCP    [::1]:49286            Daniel:49286           ESTABLISHED     4280

After discovering the process ID, which is displayed in the last return column of the command, just search for its name using tasklist:

C:\Users\Daniel>tasklist /FI "PID eq 4280"
Image Name                     PID Session Name        Session#    Mem Usage
========================= ======== ================ =========== ============
firefox.exe                   4280 Console                    1    601.012 K

Or you can just kill the process with taskkill:

C:\Users\Daniel>taskkill /PID 4280

Answer 2

In my case it was the default website that was running and using the application port. Just stopped the site, I took advantage to run the VS in administrator mode.