How I Converted My MyBook for Mac to Work on Windows as NTFS

I’ve managed to recover from a series of dumb decisions and am finally enjoying the lovely 1TB MyBook that I bought back in, wait for it, September. I’d made the mistake of looking at a MyBook for Mac as well as the MyBook I planned to order. Then I made the further mistake of closing windows. Then of reopening the wrong one. Then of ordering the wrong one. Then when I got the wrong one, I went into a shame spiral that’d be better illustrated by Allie Brosh but basically consisted of me being terrified of either returning or opening the damn thing.

Finally, I screwed up my courage, decided that I probably wasn’t going to return it, and started looking for solutions. MyBook for Mac, you see, uses GPT (GUID Partition Table) whereas Windows uses NTFS or FAT32 and won’t read GPT. I tried out the trial version of MacDrive, which is supposed to let one manage external drives with GPT, but it didn’t work. So reformatting it was. That’s probably better in the long run, anyway.

It was shockingly hard & surprisingly easy to find the info for reformatting the drive. I tried Google, first, which yielded some people with the same problem, but no good results. Fortunately, Western Digital has either run into enough people who’ve made this mistake or had enough people switch systems that they’d written up a series of tutorials I used.

First, I followed the instructions to write zeros to the drive. I had to write zeros to the whole thing, which I let run overnight, because the shortcut didn’t work. It still gave me an error message at the end, but I was able to see the drive to initialize it in the second step.

Next, I initialized the drive on my system. It had kind of an interesting result. The small part of the drive that’d been showing up before (the part with synch software, which is visible in both kinds of OSes, though not really useful in Windows) was still showing up, but now there was a second disk…one that the computer thought was one of its own disks. The second disk showed up as unformatted, unpartitioned, and just the right size.

So then I partitioned and formatted the disk, again following their instructions carefully. That took a while, as well, but when it was done the drive actually worked. It doesn’t pop up when plugged in, the way an external drive often does, because it thinks it’s part of the computer. But it functions just fine.

I’ve been backing up my old 500GB hard drive onto it. Because I was a little nervous, I tried accessing the files on the drive to see if music could be played, videos watched, documents read. Everything seems to be working just fine. Now I have to figure out what my game plan will be for using the two drives, how much redundancy I want, and which as-yet-unripped tv series I want to add to the ones I’ve already backed up on there.

I wrote this post partly because I’m so happy I’ve finally got it working and partly because I wanted to assemble those three tutorial links. While finding them on the knowledge base wasn’t too hard, it wasn’t as easy as it should’ve been. I also accept no liability for your attempts to format your MyBook & caution that those attempts my void any warranty or returnability. The linked instructions are on Western Digital’s site & therefore their responsibility.


  1. Booo says:

    Thank you very much…

    so now you have 2 seperate hard drives in one external?

  2. Ruth says:

    Yes, but the smaller hard drive is only 443 MB and has no free space on it. So one should be wary of its showing up as two, but it’s only one usable HD. Now if I’d wanted to, I could’ve partitioned two parts of the HD, but I didn’t see any particular benefit, so I made the remainder all one drive.

  3. Viking2121 says:

    I know this old, But I did come by a 2tb My Book For Mac external HDD for $50 bucks, I needed another back up drive anyway, so not knowing much about Mac and its OS or how they change the filesystem, I thought it would work or simply format it and it will work. Well it didn’t and it wasn’t even detected by windows that it was plugged into the USB port. I took it all apart (is isn’t going back together lol) and plugged it into 1 of my sata channels and Win 7 picked it up but I couldn’t use it. I came crossed this tutorial and Im in the process of Write Zero’s (entire drive). Says I have 4 hours, but it keeps going up. If this works, which I am sure it will. I will be 1 happy camper to get a 2TB for $50, even if I had to do extra things to get it to work.

    thanks so much for this guide Ruth!

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