We have an iMac at home and want to use our Western Digital 2TB My Book Studio for storing all our digital photos and movies. Since we updated our iMac's operating system to Lion, Western Digital 2TB My Book Studio will not not appear in network anymore

Connect the drive directly to the Mac, not to the router.

Does it show up in Disk Utility?

Check that the data cable is securely inserted at both ends.

Try a different cable.

If you're connecting the drive through a hub, connect it directly to a built-in port on the Mac.

If you're connecting it directly, try a different port.

Disconnect all other devices on the bus, or as many as possible.

Test the drive with another Mac. Test another drive with this Mac.

If the drive is bus-powered, but has an AC adapter, connect the adapter.

Boot into Recovery and launch Disk Utility. Is the drive recognized?

If the drive doesn't work under any of the above conditions, and if another drive does work with the same Mac, then the drive has failed. You may be able to salvage the mechanism by removing it from the enclosure and installing it in another one, or in a drive dock.

Try resetting the

SMC RESET

http://support.apple.com/kb/HT3964

• Shut down the computer.
• Unplug the computer's power cord and ALL peripherals.
• Wait 15 seconds.
• Attach the computers power cable.
• Wait another 5 seconds and press the power button to turn on the computer.
• It is the 5 second timing that initiates the reset.