Apparatus and method for in situ authentication and diagnostic repair of a data storage device in a multi-device user environment. In accordance with some embodiments, the method includes detecting an error condition associated with a selected data storage device in the multi-device user environment. A first level of user authentication is established by providing a challenge value generated by the selected data storage device to a remote device over a network associated with the selected data storage device. A first diagnostic tool stored on the selected data storage device is executed responsive to receipt of the first level of user authentication. A second level of user authentication is established by providing a second challenge value generated by the selected data storage device to the remote device. An output from the first diagnostic tool is used to execute a second diagnostic tool stored on the selected data storage device.