Specifies the initial "window" for TCP connections. One side of a TCP connection tells the other side how much data it can send before receiving an acknowledgement. This solves the problem of having to acknowledge every transmission. The larger this value, the higher the performance, but at the cost of more memory being used per connection. Windows NT 4.0 used a default value of 8760, whereas Windows 2000 doubled that to 17520. This means that Win2k will transfer bulk TCP data faster than WinNT, but use twice as much memory for buffering each TCP connection.
The maximum size of this parameter is 64240 for WinNT and individual interfaces on Win2k.
For best performance, this value should be a multiple Ethernet Maximum Segment Size (MSS).
On Win2k, this parameter can also be set on a per interface basis using HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\interface\TcpWindowSize. On WinNT, this parameter is set on a per interface basis using HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\interface\Parameters\Tcpip
