QoS Bandwidth Reserve Setting By default, Windows XP reserves 20% of the connection bandwidth for QoS traffic. This tweak allows the setting to be altered to a different percentage of connection bandwidth. If the system uses more than a single adapter for network connections, each adapter may be set individually by navigating to: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Psched\Parameters\Adapters\{Adpater-ID} rather than HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Psched [Start] [Run] [Regedit] Registry Key: HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Psched Modify/Create the Value Data Type(s) and Value Name(s) as detailed below. Data Type: DWORD Value // Value Name: NonBestEffortLimit Setting for Value Data: [Enter as a Percentage / Default Value = 20] Exit Registry and Reboot For a better understanding of QoS, see the link listed below. There have been a number of articles/tweaks published that contain misleading information about performance gains that can be obtained through QoS manipulation. The article below contains the following section: Correcting Some Incorrect Claims About Windows XP QoS Support There have been claims in various published technical articles and newsgroup postings that Windows XP always reserves 20 percent of the available bandwidth for QoS. These claims are incorrect. The information in the "Clarification about QoS in End Computers That Are Running Windows XP" section of this article correctly describes the behavior of Windows XP systems.
Click Start-->Run-->type "gpedit.msc" without the " This opens the group policy editor. Then go to: Local Computer Policy-->Computer Configuration-->Administrative Templates-->Network-->QOS Packet Scheduler-->Limit Reservable Bandwidth Double click on Limit Reservable bandwidth. It will say it is not configured, but the truth is under the 'Explain' tab : "By default, the Packet Scheduler limits the system to 20 percent of the bandwidth of a connection, but you can use this setting to override the default." So the trick is to ENABLE reservable bandwidth, then set it to ZERO. This will allow the system to reserve nothing, rather than the default 20%.