Changing default TCP window size using registry key

Using this registry DWORD value - TcpWindowSize  in HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters to change the default TCP Window Size does not seem to improve the perfromance of the throughput. It seems this reg key doesn't work any more.

https://learn.microsoft.com/en-us/troubleshoot/windows-server/networking/description-tcp-features#tcp-window-size