Friday, March 4, 2011

If you have Skype running and you use IIS with ports: 80 and 443 - you may be in trouble

      I've been using Skype for the last year as a primary messaging solution and newer had any problems until a few weeks ego. All of the sudden, my computer start show all kind of network issues where main would be a failure to run any of the web applications on a local IIS 7.0. When I tried to start default web application or any other applications - IIS prodused the following error:

"The process cannot access the file because it is being used by another process."

The System's log error looks like this:

Log Name:      System
Source:        Microsoft-Windows-IIS-W3SVC
Event ID:      1004
The World Wide Web Publishing Service (WWW Service) did not register the URL prefix http://*:80/WebApps for site 1. The site has been disabled. The data field contains the error number.

To find out what is causing the issue, I scanned my network for an applications listening on ports 80 and 443 by executing the following commands :

netstat -aon | find ":80"
netstat -aon | find ":443"

Here is what I got as a result:

TCP                 LISTENING       10024
TCP               LISTENING       10024

When I checked my task manager, I found that this process ID 10024 belongs to Skype.
Having this information, the fixing was a matter of minutes:
  • Within Skype, select Tools from the top menu
  • Select Options
  • Select Advanced from the left sidebar
  • Select Connection from the Advanced sub-menu
  • Uncheck the Use port 80 and 443 as alternatives for incoming connections checkbox
Here is a screen-shot of the Skype with advanced settings menu opened: