20 Most Recent Seagate FreeAgent Pro Desktop - 320GB - 7200rpm - 480Mbps USB 2.0, 300Mbps External SATA ... Hard Drive - Page 6 Questions & Answers

Connect HD in another computer as a slave drive.

power adapter

Has it been formatted? Have you ever had it working? Is there a clicking sound coming from it? Please click the Comment link to respond.

Try connecting it to a different port

Go to the Seagate site and under support you should find some tools to check the condition of your hard drive. If your drive is old it may not be able to deliver the movie fast enough.

did you install the enhanced drive as instructed if not don't complain

if you don't have a backup as a precaution I would do a full back up and get a new hard disk because the one you're referring to might be slowly on his way out

Get Testdisk and see if the drive is recognised. If so try to create a new boot sector.

hard drive failure is a mechanical fault needing a new hard drive to fix it

Take the drive out he caddy and plug it into another computer to see if it still works. If the drive is dead then you need another drive.

Then the drive has failed.