You have a Windows 7 multiprocessor system and USB device which supports selective suspend. When the USB device driver detects inactivity, it requests to put the device in a low power state (D2). Later, when the device is required for an I/O operation, the device driver sends a request to resume the device to full power (D0). Occasionally, when the USB device resumes from D2 to D0, the device driver may receive an unexpected USB bus reset. This causes the device to be surprise removed and as a result, a new device arrival notification and re-initialization occurs for the device. During this time, the USB device may disappear and re-appear. For example, if the device is a USB networking adapter, the network connection will be temporarily lost and re-established.
Article ID: 2444420 - Last Review: Aug 16, 2011 - Revision: 1