You don't say what kind of failure it was - but if it was read errors or faulty sectors, as opposed to complete failure where you can't even see the drive in the BIOS, the best bet for recovering data is to buy a copy of SpinRite (see
http://www.grc.com/sr/spinrite.htm) and run it against the drive.
Obviously it's just software and it can't fix hardware faults, nor can it always fix bad sectors, but in my experience it often can either recover all or most of the data, or allow the drive to be accessed again when Windows can't get to it.
And if you use a Mac, it can be run against those disks too if you first put them in a Windows box.