Windows Vista - http://www.vistaarticles.com
Windows cannot load the device driver for this hardware because there is a duplicate device already running in the system. (Code 42)
http://www.vistaarticles.com/articles/502/1/Windows-cannot-load-the-device-driver-for-this-hardware-because-there-is-a-duplicate-device-already-running-in-the-system.-%28Code-42%29
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Published on 11/16/2007
 
Windows cannot load the device driver for this hardware because there is a duplicate device already running in the system. (Code 42)
Duplicate device already running in the system. (Code 42)

A duplicate device was detected. This error occurs when a bus driver incorrectly creates two identically named children (bus driver error), or when a device with a serial number is discovered in a new location before it is removed from the old location.

Restart the computer.