Article ID: 810703
Article Last Modified on 1/16/2004
APPLIES TO
- Microsoft Windows 2000 Service Pack 3
- Microsoft Windows 2000 Service Pack 3
SYMPTOMS
After installing Windows 2000 Service Pack 3, an Unsafe Removal of Device dialog box may appear when a user resumes from the Suspend state (S3) or from the Hibernation state (S4), although no device has been removed.
This problem has been seen only when a universal serial bus (USB) 1.x storage device (that is, a floppy disk or a hard disk) is attached to a USB 2.0 port. The dialog box will reference the USB 1.x storage device although it is still connected.
Users do not experience this behavior if the drivers for USB 2.0 support in Windows 2000 are not installed.
CAUSE
The dialog box appears because a Windows 2000 timing issue involves turning on (or "powering up") both the USB companion controller driver stack and the Enhanced Host Controller interface (EHCI) stack after resuming from suspend.
RESOLUTION
To resolve this behavior, close the Unsafe Removal of Device dialog box.
STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section of this article.
MORE INFORMATION
If the companion controller root hub driver turns on first, the USB 1.x devices that were attached to the root hub ports when the computer entered suspend are no longer attached. Therefore, the driver informs Plug and Play that the device has been removed.
This behavior occurs because although the devices were routed to the EHCI controller when the Configure flag was set, they are not currently attached to the companion controller. When the EHCI controller (for USB 2.0) root hub driver later turns on, the root hub ports are reset and USB 1.x devices are routed back to the companion controllers. Next, the companion controller hub enumerates the devices again, after which they are detected and become functional.
This process does not affect USB 2.0 devices because they always remain attached to the EHCI controller.
For additional information about USB 2.0 support in Windows XP, click the following article number to view the article in the Microsoft Knowledge Base:
319973 Universal Serial Bus 2.0 Support in Windows 2000
Additional query words:
Keywords: kbprb KB810703
