The Drive Letters for Docking Station Devices May Change When Hot Docking a Laptop Computer (295429)

SYMPTOMS

When you use a hot docking operation to place your laptop computer into a docking station that has both AT Attachment Peripheral Interface (ATAPI) and universal serial bus (USB) devices attached, the drive letters for those devices may change.

CAUSE

This behavior can occur because of the different enumeration processes that occur when your laptop computer is hot docked versus when it is undocked. When you start your laptop computer while it is undocked, the devices that are attached to the Integrated Device Electronics (IDE) controller are enumerated before the devices that are attached to the USB. When your laptop computer is hot docked, this process is reversed and the USB devices are enumerated first.

WORKAROUND

To work around this behavior, manually assign the drive letters to the appropriate drive in Device Manager:

Click Start, point to Settings, click Control Panel, and then double-click System.
Click the Device Manager tab, and then double-click the CD-ROM branch to expand it.
For each CD-ROM drive that is listed, select the drive that is listed under the CD-ROM branch, click Properties, click the Settings tab, and then change the "Start drive" and the "End drive" letters to the appropriate setting.
Click OK, click OK, and then restart your computer.

NOTE: If the devices that are attached to either the IDE or USB controllers are hard disks, they are listed under the Disk Drives tree in Device Manager.

MORE INFORMATION

The following computers are known to be affected by this behavior: IBM ThinkPad Models A2x, T2x, X2x, and any other ThinkPad that supports the ThinkPad dock.

The third-party products that are discussed in this article are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, regarding the performance or reliability of these products.