Go to programs, accessories then right click command line and select run as administrator.

At the prompt type

netsh interface tcp set global autotuninglevel=disable
__________

Vista: TCP window scaling not compatible with some network hardware.

There is an incompatibility between Microsoft Windows Vista and some network equipment. Equipment possibly affected includes: Routers, VPN Endpoints, and Firewalls that use Stateful Packet Inspection (SPI).

Among most commercial firewalls that utilize Stateful Packet Inspection, the OSU Fire Marshall is one that is affected by this issue.

The problem has to do with the TCP window resizing feature in Vista and Stateful Packet Inspection. Possible symptoms exhibited include:

• Web traffic works OK
• Email through client software sends but will not receive or times out when downloading messages (POP or IMAP)
• Slow or no network file server access.
• Other random network timeouts or connectivity problems.
• Slowness or freezing in web browsing or other applications including VPN connections.

To disable TCP Windows Scaling In Vista:

1. Note: This command MUST be run as administrator
2. Locate the Command Prompt icon/executable file under Start->Accessories
3. Right-click on the icon and select “Run as administrator”
4. Type: netsh interface tcp set global autotuninglevel=disabled
5. Reboot the computer.

To verify the settings on the workstation, use the command:

netsh interface tcp show global

The results of this command should be:

TCP Global Parameters
_____________________

Receive-Side Scaling State                 : enabled
Chimney Offload State                      : enabled
Receive Window Auto-Tuning Level           : disabled
Add-On Congestion Control Provider         : ctcp
ECN Capability                             : disabled
RFC 1323 Timestamps                        : disabled