Some Universal Serial Bus (USB) devices that are attached to the computer may perform poorly or not work at all when other, or all, connected USB devices are being used.

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This behavior can occur if the data transmission bandwidth demands of the combined USB devices exceed the available bandwidth.

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To resolve this issue, add an additional USB host controller to the computer and attach some of the USB devices to it to share the bandwidth load.

To work around this issue, remove the devices that are using the most bandwidth. To determine which devices are using available bandwidth:

1.	When the problem is occurring, right-click My Computer, and then click Properties.
2.	Click the Device Manager tab.
3.	Click the plus sign (+) next to Universal Serial Bus Controllers.
4.	Double-click the listed USB universal host controller.
5.	Click the Advanced tab.
6.	Click Bandwidth Usage.
7.	Check to see which devices consume the most bandwidth. The amount of bus bandwidth a device uses appears as a percentage of all available bandwidth.

You may want to attach the devices that consume the most bandwidth to a separate USB host controller's hub, or remove a device from the bus so that the remaining devices have more available data transmission bandwidth.

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