If the network connection is OK and your Avira antivirus doesn't block the software, make sure that your Windows firewall allows the the program to connect. Go to Start > Control Panel > System and Security > Windows Firewall > Allow a program through Windows Firewall and check the box next to Volvo Penta Synchronizer. If you can't find the application in the Allowed programs and features window, press the Allow another program button, navigate to the installation directory, select the executable file and press Add. After that, from the Advanced Settings select Inbound Rules > New Rule. Check the Port box, click Next, select All local Ports and follow the self-explained steps. If the problem persists, reinstall the Volvo Penta Synchronizer program.