First, try to reinstall the application because it is possible to not be installed correctly. After that, go to Start > Control Panel > System and Security > Windows Firewall > Allow a program through Windows Firewall and click Allow another program button. Use the Browse option to navigate to MobeeStar installation directory, select its executable file and press Add. Also, make sure that your antivirus program doesn't block the connection. If you still have issues, I suggest you to download and install another PC dialer from the developer's web page.