HOW TO DISABLE WINDOWS VISTA TCP/IP AUTO-TUNING

SOMETIMES IT IS HELPFUL TO DISABLE WINDOWS VISTA'S AUTOTUNING OF TCP/IP.

SOME NETWORKING DEVICES,SUCH AS SPI FIREWALL,SOME NAT ROUTERS,VPN ENDPOINTS,   WIFI   DEVICES HAVE   PRONLEMS   WITH THE WAY WINDOWS VISTA RESIZES THE   TCP   WINDOWS.POSSIBLE   SYMPTOMPS   INCLUDE:WEB TRAFFIC OK,EMAIL  TIMEOUTS ON RECEIVING ONLY,SLOW OR NO NETWORK FILE SERVER ACCESS,RANDOM NETWORK TIMEOUTS OR CONNECTIVITY PROBLEMS, FREEZING OR SLOW WEB BROWSING OR VPN  CONNECTIONS.

NOTE THAT DISABLING TCP WINDOWS  AUTOTUNING LIMITS THE WINDOWS TO 65535, WHICH MAY NOT BE ADEQUATE FOR BROADBAND INTERNET CONNECTIONS.


TO DISABLE TCP/IP AUTOTUNING, IN "ELEVATED COMMAND PROMPT TYPE:

NETSH INTERFACE TCP SET GLOBAL AUTOTUNING=DISABLE

TO VERIFY THAT IT IS DISABLE

NETSH INTERFACE TCP SHOW GLOBAL

TO SET BACK TO THE DEFAULT WINDOWS VISTA BEHAVIOR

NETSH INTERFACE TCP SET GLOBAL AUTOTUNING =NORMAL

 WINDOWS HAS THE ABILITY TO AUTOMATICALLY OVERWRITE THE ABOVE USER SETTINGS,SO YOU MAY ALSO WANT TO ENFORCE THEM WITH THE FOLLOWING

NETSH INT TCP SET HEURISTICS DISABLE

NOTE: TO GET ELEVATED COMMAND PROMPT (ADMIN PRIVILEDGES), YOU  MAY NEED TO DO THE FOLLOWING:
CLICK THE START BUTTON
IN THE SEARCH BOX,TYPE:COMMAND PROMPT
RIGHT CLICK ON THE COMMAND PROMPT ICON AND SELECT "RUN AS ADMINISTRATOR"

NOTE: YOU CAN ALSO CHANGE THE DEFAULT AUTO-TUNING BEHAVIOR IN OTHER WAYS, FOR EXAMPLE TYPING THIS IN COMMAND PROMPT: NETSH INT TCP SET GLOBAL AUTOTUNINGLEVEL=HIGHLYRESTRICTED.