Forza Horizon 4 is an open world racing game that\u2019s published by Microsoft Studios and released last October 2018. Players can buy houses in the game which in turn can give them access to certain items and cars. Although this is a solid performing game there are instances when certain issues can occur. In this latest installment of our troubleshooting series we will tackle the Forza Horizon 4 doesn't connect online in windows 10 issue. Before performing any of the recommended troubleshooting steps listed below it\u2019s best to restart your computer first. This action refreshes the operating system and remove any corrupt temporary data that could be causing the problem. There are several factors that can cause this particular problem ranging from issues with the Teredo adapter to a firewall setting. Listed below are the recommended troubleshooting steps you need to do to fix this problem. How to Fix Forza Horizon 4 Cannot Connect Online in Windows 10 Try to reinstall the Teredo adapter The Teredo adapter allows your computer to work with both IPv4 and IPv6 protocols. It works in the background by making sure that you have access to online services that use either of the two protocols. If something is wrong with your PC Teredo adapter then this issue could occur which is why you will need to do a reinstallation. Press the Windows key + X hotkey and select Command Prompt (Admin).Type "netsh interface Teredo set state disable" in the Command Prompt, and press the Enter key.Right click on the Start button then click on Device Manager.Click View and select Show hidden devices.Double-click Network adapters to expand that device category.Then right-click any Teredo adapter listed there and select Uninstall.Restart Windows after uninstalling the adapter.Open an elevated Command Prompt again.Type "netsh interface Teredo set state typedefault" and press Enter to re-enable the adapter. Then the adapter will reinstall automatically. Check if you can play Forza Horizon 4 online. Make sure the Windows Firewall is on While you will sometimes need to turn off the firewall when experiencing issues with certain games it is different for this title. This game requires that the Windows Firewall is turned on as it will need the Teredo IPsec connection. Open up the command prompt make sure to select Run as Administrator.On the command prompt, type "netsh advfirewall set allprofiles state on".Close the Command Prompt Try to check if the game can connect online. Turn off the antivirus The antivirus software installed in your computer could be interfering with the Teredo IPsec connection which in turn can cause this problem. To eliminate this possibility you will need to turn off the antivirus. Avast Right-click on the avast! icon in the system tray. Select avast! shields control and there will be options to disable avast for 10 minutes, 1 hour, until the computer is restarted or permanently. Bitdefender Double click on the system icon for Bit Defender.When the Bit Defender window appears, move the mouse arrow to the left side and click >> Virus Shield.Move mouse arrow to the black check by Virus Shield is enabled and click.The black works will change to red, >> Virus Shield is disabled.Move mouse arrow to the top right corner and click the down arrows.Bit Defender is now inactive.To enable Bit Defender, do the same steps except click to enable. Microsoft Security Essentials Right-click on the MSE icon in the system tray and choose Open.Click the Settings tab, then click Real Time Protection.Uncheck the box next to "Turn on real time protection".Click the "Save changes" button.Exit MSE when done. ESET Double click on the system tray icon to open the main application window.Or via Start >> All Programs >> ESET >> ESET Smart Security.Click Setup >> Antivirus and antispyware >> Temporarily disable Antivirus and antispyware protection.When prompted to confirm temporarily disable select Yes.Note: Protection will be automatically started after a system reboot. McAfee Navigate to the system tray on the bottom right hand corner and look for the McAfee icon.Right-click it -> chose "Exit"A popup will warn that protection will now be disabled. Click on "Yes" to disable the Antivirus guard. Check if the Forza Horizon 4 can\u2019t connect online issue still occurs. Uninstall the VPN software If you are using a VPN software as this might be preventing the game from going online. Right-click Windows 10\u2019s Start button and click Device Manager.Select Show hidden devices on the View menu.Double-click the Network Adapters category in Device Manager.Right-click the VPN\u2019s TAP adapter and select Uninstall.Restart Windows 10 after uninstalling the adapter. Try to check if the Forza Horizon 4 won't connect online issue still occurs. Make sure the IP Helper Service is enabled The IP Helper helps in the network administration of the computer by enabling applications to retrieve information about the network configuration of the computer, and to modify that configuration. This service needs to be enabled in order for the game to run properly. Type Run in the search bar then open the run application.Type "services.msc" in Run\u2019s text box, and press the OK button.Double-click the IP Helper service.Select Automatic on the Startup type drop-down menu.Click the Start button.Press the Apply button to apply the new settings.Click OK to close the window. Check if the Forza Horizon 4 will not go online issue still occurs. Enable Xbox Live Networking\/ Xbox Live Auth Manager Services Type Run in the search bar then open the run application.Type "services.msc" in Run\u2019s text box, and press the OK button.Double-click the Xbox Live Networking service.Select Manual on the Startup type drop-down menu.Click the Start button.Press the Apply button to apply the new settings.Double-click the Xbox Live Auth Manager service.Select Manual on the Startup type drop-down menu.Click the Start button.Press the Apply button to apply the new settings.Click OK to close the window. Check if the Forza Horizon 4 can't connect online problem still occurs.