There may be situations where a system is having problems establishing a reliable Internet connection. This could occur after an update to the operating system or a network driver, or after the installation of third-party software such as a VPN. Fortunately, it's not difficult to reset your system back to its default configuration and restore connectivity.
To use these commands, you will need to open an administrative command prompt or PowerShell. To completely reset the TCP/IP stack, enter the following command:
netsh interface ip reset
This will effectively replace the TCP/IP and DHCP configuration properties in the system registry, restoring them to their default values.
This will remove static IP information for all network interfaces configured on the system. If you have assigned static IPs to one or more of your NICs, you will need to reconfigure them with their IP address, netmask and gateway values.
If you get an error, this typically indicates that you're either attempting this command without appropriate permissions, or there is an anti-virus program which is interfering with its ability to make changes to the registry. In this case, you may need to temporarily disable your anti-virus software and then re-enable it when you're finished.
Next, you can reset the Windows Sockets (Winsock) configuration with the command:
netsh winsock reset
This can correct issues with improperly configured network devices and reset everything back to its default state. You can also reset the TCP/IP v4 and TCP/IP v6 interfaces using the following commands (if you don't have IPv6 enabled at all, you can skip the second command):
netsh interface ipv4 reset
netsh interface ipv6 reset
After these steps have been completed, reboot your system and everything should be back to its original state when the TCP/IP stack was first configured during the Windows installation process.