I am attempting to swap the factory 500GB 5400rpm drive in an early 2011 15" MacBook Pro to a 1TB 7200rpm for a relative. The Pro doesn't seem to like the it however, even though it works perfectly fine in another MacBook (late 2009) and over Target Disk Mode. Here's what I've tried so far: 1. Restoring the Time Machine backup directly to the drive. "Could not create recovery disk" 2. Installing a clean copy of Mavericks (and later Yosemite) to the drive from a bootable USB. Failed. 3. Installing Lion from a late 2006 iMac to the drive over Target Disk Mode. The install was successful, however the Pro didn't boot...it only Kernel Panicked. The iMac was able to boot successfully however. 4. Installing Yosemite on the new drive in the MacBook (which completed perfectly), and then swapping the drive to the Pro. Hangs on boot with the progress indicator approximately one third complete. Verbose mode states that there is an "I/O error". 5. Resetting NVRAM. No change 6. Installing Snow Leopard from the restore DVD. Failed I do not currently have a Firewire 800 to 800 cable, (only an 800 to 400) but if it is likely that an install of Yosemite (or direct Time Machine restore) from my 2011 iMac will work, then I would be happy to purchase one. Any suggestions would be greatly appreciated. Thank you.