Fix Problems With Copying Large Files in Windows Vista

If you’ve been having problems copying large files over mapped drives, network disconnects, or having to reboot your router a lot more often than normal, then you can try out this fix to solve the problem.

The problem stems from the new auto-tuning network, which changes the receive window on the fly. Thankfully we can easily turn it off from an administrative mode command prompt.

Open Administrative Mode Command Prompt

Either type cmd into the start menu and use Ctrl+Shift+Enter or right-click the Command Prompt shortcut and choose Run as Administrator.

Turn Off Auto-Tuning

netsh int tcp set global autotuninglevel=disabled

You’ll have to reboot your system, but once you do, the problems should be resolved. If they are not you can always turn auto-tuning back on.

Turn On Auto-Tuning

netsh int tcp set global autotuninglevel=normal

For more information on this topic, you can read this article from MSDN blogs.