Tried the Western Digital 640 GB WD Blue SATA II 5400 RPM 8 MB Cache Bulk/OEM Notebook Hard Drive, but it does not work. Is it something to do with sectors? Does the machine need something else to be able to replace the hard drive? Which hard drive would work as a replacement, and where do I look for how-to instructions? This is a late 2006 MacBook "Core 2 Duo." Thank you.