A slow network performance can have a huge variety of causes.
This is a local soultion to improve network performance by increasing
the TCP Window Size.To change the TcpWindowSize entry to a higher value navigate to:


- HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet
\Services\Tcpip\Parameters\


Focus in the right pane on the entry :


TcpWindowSize


Doubleclick it and set it's value to a higher value as it is.


Note:
The default value is 8760 (Decimal) for Ethernet.You can give it a value
between 0 and 65535 (Decimal)