NIC Card Speed problem HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters and add Value name TcpWindowSize as type REG_DWORD and set it to 2920 (decimal). Note: This tip is for 100MB EtherNet TCP/IP networks only. Using this parameter on a 10MB network, or on a WAN or FDDI, or Token Ring, or anything else, will impact performance.