Will upgrading to Mavericks disable my Mybook Studio and MyPassport Ultra?

Hello,

Please see the following link.

http://wdc.custhelp.com/app/answers/detail/a_id/11005/related/1/session/L2F2LzEvdGltZS8xNDAxMzAzOTcyL3NpZC9WSzFEUXBWbA%3D%3D

After the Maverick update and before you plug the unit back in please follow the instructions on the link above to make sure you have a version of the software that is fully compatible with the new OS.

Yes, make sure that the drive is not connected at the time of the update.