How-To Geek

Speed Up Network File Copying While Playing Audio in Windows Vista SP1

Note: This article is part of our archive and is likely out of date.
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Windows Vista restricts network traffic to 10 packets per millisecond while playing multimedia to prevent skipping. Unfortunately this causes network speed to be pitiful on a gigabit network, especially during file copies over the network.

Service Pack 1 includes a new registry tweak that can be used to change the throttling percentage so you can at least partially fix this problem, but you should be careful to test it out, because you don’t want your audio to skip either.

Note: This setting is only really useful if you are on a gigabit network – the default values should be fine for a Wireless network.

Manual Registry Hack

Open regedit.exe through the start menu search or run box, and then browse down to the following key:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Multimedia\SystemProfile


You will see a value on the right-hand side named NetworkThrottlingIndex, which can be changed to anything from 1 to 70 (decimal). I would recommend testing out different values to see what works for you. Note that you’ll need to reboot after making this change.

The Anandtech website has more information and test notes for this hack… note the difference in the graph below (from their site), the top graph is before the registry hack, and the bottom is after.


For more information you can also read the Microsoft KB article on the subject.

Lowell Heddings, better known online as the How-To Geek, spends all his free time bringing you fresh geekery on a daily basis. You can follow him on if you'd like.

  • Published 03/24/08

Comments (5)

  1. Planet Lowyat

    Cool! The stupid M$ created stupid restriction.

  2. timothy

    Very useful information, how’d you manage to find that one? Please tell me you don’t read KB articles for fun ;-)

  3. dcj2

    Nice tip, though I imagine it could irritate your friendly neighborhood SysAdmin.

    Also, does anyone else find it mind boggling that here in the age of Vista, we’re *still* navigating to hklm\…\WINDOWS NT. I mean seriously, will MS ever get around to ditching some of that old, old code?!?!?!

  4. Fird

    Thanks for the tip! I thought my gigabit switch is under performing. This speeds up copying/syncing folders tremendously!

  5. jd2066

    @dcj2: Actually that key makes since as Windows 2000/XP/Vista are all versions of Windows NT.
    Windows 2000 is Windows NT 5.0
    Windows XP is Windows NT 5.1
    Windows Vista is Windows NT 6.0
    The names were changed for marketing reasons.

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