OK, my team has found a solution to our problem. Here are the steps:
1. Running as Administrator in Command Prompt, type: “netsh int tcp set heuristics disabled”
2. Next, follow the instructions that Amrita wrote above.
First enter: “netsh int tcp set global autotuninglevel=disabled” and reboot.
Then enter: “netsh int tcp set global autotuninglevel=normal” to restore it to the typical setting.
3. Finally, go to Control Panel > Programs > Turn Windows Features on or off > and check “Simple TCPIP services (i.e. echo, daytime, etc.) so that it is enabled.
4. Reboot your system again, and the file transfer rates should be excellent.