Reformatting an External HD

[Mac Curious]

I have an external HD that I've used to backup my MacBook Pro. I now want to transfer files to a PC with Windows 8, but the Windows machine doesn't recognize the external HD. After reading some posts on this forum, it seems that the external HD needs to be formatted differently. My question is, if I reformat the HD, will the data on the drive be lost? Thanks.

 

[grapes911]

if I reformat the HD, will the data on the drive be lost?

Yes. Reformatting the drive will erase all data.

 

[simsaladimbamba]

Look at the HFS+ (Mac OS Extended) section to find out, how to read a Mac formatted HDD within Windows.
And yes, formatting any HDD will erase the data.

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Overview of the four major file systems (called "Formats" in Mac OS X) used on Windows and Mac OS X, compiled by GGJstudios. You can use Disk Utility to format any HDD to your liking.

Any external hard drive will work with PCs or Macs, as long as the connectors are there (Firewire, USB, etc.) It doesn't matter how the drive is formatted out of the box, since you can re-format any way you like. Formatting can be done with the Mac OS X Disk Utility, found in the /Applications/Utilities folder. Here are your formatting options:

HFS+ (Hierarchical File System, a.k.a. Mac OS Extended (Journaled) Don't use case-sensitive)

• Read/Write HFS+ from native Mac OS X
• Required for Time Machine or Carbon Copy Cloner or SuperDuper! backups of Mac OS X system files.
  [*]To Read/Write HFS+ from Windows, Install MacDrive
  [*]To Read HFS+ (but not Write) from Windows, Install HFSExplorer
• Maximum file size: 8EiB
• Maximum volume size: 8EiB
• Mac OS X: Mac OS Extended format (HFS Plus) volume and file limits
• You can use this format if you only use the drive with Mac OS X, or use it for backups of your Mac OS X internal drive, or if you only share it with one Windows PC (with MacDrive installed on the PC)

NTFS (Windows NT File System)

• Read/Write NTFS from native Windows.
• Read only NTFS from native Mac OS X
  [*]To Read/Write/Format NTFS from Mac OS X, here are some alternatives:
  • For Mac OS X 10.4 or later (32 or 64-bit), install Paragon (approx $20) (Best Choice for Lion)
  • For 32-bit Mac OS X, install NTFS-3G for Mac OS X (free) (does not work in 64-bit mode)
  • For 64-bit Snow Leopard, read this: MacFUSE for 64-bit Snow Leopard
  • Some have reported problems using Tuxera (approx $36).
  • Native NTFS support can be enabled in Snow Leopard and Lion, but is not advisable, due to instability.
• AirPort Extreme (802.11n) and Time Capsule do not support NTFS
• Maximum file size: 16 TB
• Maximum volume size: 256TB
• You can use this format if you routinely share a drive with multiple Windows systems.

exFAT (FAT64)

• Supported in Mac OS X only in 10.6.5 or later.
• Not all Windows versions support exFAT. See disadvantages.
• exFAT (Extended File Allocation Table)
• AirPort Extreme (802.11n) and Time Capsule do not support exFAT
• Maximum file size: 16 EiB
• Maximum volume size: 64 ZiB
• You can use this format if it is supported by all computers with which you intend to share the drive. See "disadvantages" for details.

FAT32 (File Allocation Table)

• Read/Write FAT32 from both native Windows and native Mac OS X.
  [*]Maximum file size: 4GB.
• Maximum volume size: 2TB
• You can use this format if you share the drive between Mac OS X and Windows computers and have no files larger than 4GB.

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