Once again, Microsoft thinks it can solve all of your problems by being smarter than you are. Unfortunately, some of the “automatic tuning” features of Vista can yield in lower performance (read our article on how SuperFetch may actually decrease performance).
One of Vista’s features tries to change the network’s receive window on-the-fly to adapt to changing network conditions. If you’ve been experiencing lower network throughput when transferring large files or experience weird network disconnects, then you can try disabling Vista’s auto-tuning network feature.
Open a Command Prompt in Administrative Mode. You can do this by typing “cmd” in the Start Menu and pressing Ctrl+Shift+Enter to execute. You can also do this by right-clicking the Command Prompt shortcut and selecting “Run as Administrator”. You can also read our article on always enabling Administrator mode.
Type “netsh” and press Enter. You are now in the netsh command mode.
Type “int tcp” and press Enter.
Type “set global autotuninglevel=disabled” and press Enter. The command prompt should return “OK”.
Type “exit” to return to the normal command prompt.
After changing this setting you will have to reboot to see if your network troubles are over. You can always turn this setting back on by repeating these steps but typing “set global autotuninglevel=normal“.