I have a new 4.0 TB Black hard drive from Western Digital that I mounted in a Lacie external enclosure after removing a 2.0 TB drive. My new MacBook Pro's Disk Utility wants to initialize this disk but only recognizes the capacity as 1.8 TB. This is the second 4.0 TB disk with the same problem as the first was returned under warranty when the capacity didn't change after writing 0's and formatting (initializing) the disk. Western Digital's Data Lifeguard Diagnostics for Windows on my Windows XP machine sees the entire 4.0 TB and their Support Technicians suggested I write zero's across the entire disk then format it in my Mac. However, Windows XP installed software updates on it's own and rebooted after 27 hours of writing zero's (only half way completed)! To start writing zero's again would take another 48 hours. What is going on here? I thought the current BIOS in todays Mac's AND PC's would read the full capacity accurately since the earlier 2.0 TB read limit debacle of a few years ago. Can anyone offer a Mac resolution or suggestion to get a full 4.0 TB hard drive my MBP can read? Thanks to all that may reply.