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Optimizing Broadband Internet Connections under any version of Windows
Updated: Friday October 9, 2009

WARNING: All the tips here require editing the registry, so backup the registry first by using either Registry
Checker (for Win9x/ME systems), System Restore (for WinME/XP/Vista systems) or by creating Emergency
Repair disks (for NT4 & Win2k systems).  Then run Registry Editor (regedit.exe or regedt32.exe) to
perform the tips.

You only need to modify the TcpWindowSize or DefaultRcvWindow registry value to make the most of your
broadband connection whether it is cable or DSL.

[Optimizing the TcpWindowSize value under WinNT4 SP6, 2000, XP, 2003, Vista, 2008, Win7]
This tip requires using Registry editor, so backup the registry before proceeding.
To change the TCP Window Size value for TCP/IP broadband connections go to the following key:
[NT4 users only] Create a DWORD value called 'TcpWindowSize' and set it to 00007fff (equivalent to 32767)
or 0000ffff (equivalent to 65535).  Then close Registry Editor and reboot the computer.
[Win2000/XP/2003/Vista users only]  Create a DWORD value called 'GlobalMaxTcpWindowSize' and set it
to 00007fff in hexadecimal [32767 in decimal] or 0000ffff [65535 in decimal].  Then exit Registry Editor
and restart the computer.

[Optimizing the DefaultRcvWindow value for MS TCP/IP under Win95, 98 & ME]
Go to the following registry key:
Create a string variable called 'DefaultRcvWindow' and set the value to 32767 or 65535.  Then close
Registry Editor and restart the computer.

More on optimizing/customizing TCP/IP settings at this site:

You can also check out the Navas Cable/DSL Tuning Guide page on optimizing your fast internet connection.

Actual results of these tips may vary depending on what computer is used and what network adapter,
cable modem or DSL modem & drivers used.

Also note that these tips are for broadband connections only and are worthless with dialup connections.
Tips on optimizing dialup connections are posted here.

[Click here to go back to my Computer Tips for Windows page - part 1]