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Western Digital My Book 4TB External Hard Drive

  • Model: BACW0040HBK
  • External - Desktop
  • 4.0TB
  • USB 2.0/USB 3.0
  • 5,400 rpm
  • Up to 5 Gbps
External - Desktop
USB 2.0/USB 3.0
RPM Speed
5,400 rpm
Transfer Rate
Up to 5 Gbps
Software Included
My Book Essential. WD SmartWare software: Automated backup and diagnostic software. Color: Black.
System Requirements
USB 2.0 or USB 3.0 port. Fastest transfer speeds require USB3.0 "SuperSpeed" port. Windows: WinXP, Vista, Win7. Mac OSX: Leopard or later (requires reformatting)
5.3(w) X 6.5(h) X 1.9(d)
Shipping Weight
4 lbs
Warranty Terms - Parts
12 Months
Warranty Terms - Labor
12 Months

WD's Solution Assistant


Ideal For

  • Connecting with your USB 2.0 port today and using with USB 3.0 when you're ready.
  • Transferring files up to three times faster when connected to a USB 3.0 port.
  • Protecting your data with automatic, continuous backup.
  • Adding extra storage space for photos, videos and music.
  • Securing private or sensitive data with password protection and hardware encyrption.
Massive capacity. Sleek design.

Massive capacity. Sleek design.

My Book features up to 4 TB capacity, to store and protect all the chapters of your digital life.
Automatic backup.

Automatic backup.

WD’s automatic, continuous backup software works quietly in the background to help protect your data using minimal PC resources. Whenever you add or change a file, it’s instantly backed up.
Password protection secures your drive.

Password protection secures your drive.

Use WD Security to set password protection and hardware encryption and protect your files from unauthorized use or access.
USB 3.0 and USB 2.0 compatibility.

USB 3.0 and USB 2.0 compatibility.

With this single drive you get compatibility with your USB 2.0 devices today and the ultra-fast speed of USB 3.0 when you're ready to step up to the next generation.
Up to 3x faster transfer rates.

Up to 3x faster transfer rates.

When connected to a USB 3.0 port, My Book lets you access and save files with blazing speed. Reduce transfer time by up to 3 times when compared to USB 2.0 transfer rates.
WD SmartWare software.

WD SmartWare software.

WD SmartWare visual backup software provides a visual display of your backup as it happens so you know your data is safe.
Automatic, continuous backup software.

Automatic, continuous backup software.

Backup means having a second copy of your files at all times. WD's automatic backup software makes that easy. It continually works quietly in the background to help protect your data while using minimal PC resources. Whenever you save or change a file, it's instantly backed up.
Password protection for privacy.

Password protection for privacy.

WD Security utility allows you to set password protection and hardware encryption for your drive to protect your files from unauthorized use or access.
WD Drive Utilities.

WD Drive Utilities.

Register your drive, set drive security, run diagnostics and more using WD Drive Utilities.

WD quality inside and out.

We know your data is important to you. So we build the drive inside to our demanding requirements for durability, shock tolerance and long-term reliability. Then we place the drive in a robust enclosure designed for beauty and protection.




Performance Specifications

Serial Bus Transfer Rate (USB 2.0)480 Mb/s (Max)
Serial Transfer Rate
Serial Bus Transfer Rate (USB 3.0)5 Gb/s (Max)

Physical Specifications

Capacity4 TB

Physical Dimensions

Height6.50 Inches
Depth5.3 Inches
Width1.9 Inches
Weight2.60 Pounds
Height165 mm
Depth135 mm
Width48.0 mm
Weight1.18 kg

Environmental Specifications

Temperature (English)
Operating41° F to 95° F
Non-operating-4° F to 149° F
Temperature (Metric)
Operating5° C to 35° C
Non-operating-20° C to 65° C

Electrical Specifications

Current Requirements
Power Dissipation AC Input Voltage: 100-240 VAC
AC Input Frequency: 47-63 Hz

WD SmartWare

Your data is not just data, it's your family photos, your financial documents, your music - your life. You know you should back it up, but many of you don't. We understand. We've talked to lots of people and we've heard the reasons why people don't back up - there's no time; it's a pain; their data's not organized; they don't know how. Using what we've learned, we developed easy, automatic backup software we hope you'll really use because we understand the importance of your data.

It's easy.

You're up and running in a few simple steps. Once you set it up, you can forget it because the rest is automatic.
It finds your data.

It finds your data.

  • A unique visual interface lets you see the WD drives connected toyour computer.
  • WD SmartWare automatically scans your computer and finds all of your personal files, including e-mail.
  • Select the files and folders that you want backed up or back up your files by category. It's up to you.
  • The backup gauges show how much information you have to be backed up in each category. You can even mouse over a category to see afile count.
  • Simply click "Start Backup" and WD SmartWare will automatically start backing up your files.
  • As your backup is running the category gauges will change color showing you the backup as it happens.
  • When finished, you'll see a status screen and information about your backup. You only have to do this once. After the first backup, your files will be backed up automatically every time you change or add a file.
It's always on the job.

It's always on the job.

WD SmartWare is always watching your computer, so when you change a file and save it, create new files, add new pictures, movies, or songs, WD SmartWare will instantly back them up.
It's easy to bring back lost files.

It's easy to bring back lost files.

If you ever accidentally delete an important file, or need to get an earlier version of a file, you can find and retrieve it in seconds with the easy-to-use retrieve interface.
  • Restore all of the files you’ve backed up or select a particular file or folder. Use the search function to easily find a lost file.
  • Set the number of versions you want to save so you can go back in time to retrieve an older version of a file.
User Manual