Before you can update Skype, make sure that you are using a stable Internet connection. Also, make sure that Skype isn't blocked by your Windows Firewall service or by the firewall of a third party antivirus program. If you still can't update Skype, uninstall the program. After you did this, visit the review page from Software Informer to obtain a download link for the latest version. This way you should be able to install and use the latest version of the application.