Data Recovery

If this is a SATA drive, and the controller is on the motherboard, make sure the SATA-related BIOS settings are all kosher. I have seen several BIOSes mysteriously forget how their SATA controllers are supposed to be configured. source

Yeah I had the same problem with a 320gb seagate drive. I just opened it up and put it in a hard drive caddy and it worked perfect. source

So I should take the HDD out and use another HDD as the boot up drive, then attach the original HDD as a second HDD? Will there be a problem since it contains the OS as well as files? source

So I should take the HDD out and use another HDD as the boot up drive, then attach the original HDD as a second HDD? Will there be a problem since it contains the OS as well as files? source

I had such an experience what you have mentioned in your post. Couple of months ago, when I tried to import some multi-media files to my Mac Leopard Operating System, data loss occurred. I imported some mucic and presentations from my iPhone to my system using the iTunes for the backup. After when the data transfer was done, when I opened my computer and was shocked to find that the backup file was not in the memory of the system. I checked for the data on my iPhone and there also there was no data. Actually due to some bugs in the system, all my files got deleted when the backup took place. I tried accessing the data manually but I failed in the endeavor. I then used a software called Data Recovery Mac which restored all my multi media files that got deleted. Not only this, I repaired some of the damaged files bearing HFS file system using this software. You can have a look at this software, hope you recover your deleted data. source