Seagate 4TB external drive unmountable to Mac after connecting to a Windows 11 machine

[Tozovac]

I have a Seagate 4 TB spinning external drive that I’ve used for years to store various things. Used it with Mavericks, Sierra, Big Sur, and Monterey. I plugged it in once recently into my son’s Windows 11 machine, hoping to just copy a file from his computer, and it was not readable by his pc. I then went to plug it in to my M1 MBA running Monterey and the drive won’t mount. I just got off the phone with Seagate technical support who said once you plug a Mac formatted hard drive into windows, it becomes completely unreadable by a Mac computer. I am flabbergasted by this. They will be getting back to me with more possible help. We tried running disk utility and the drive won’t even mount to my MBA. We tried reconnecting it to the Windows PC hoping to get data from it and then reformat the drive but the windows PC still won’t recognize it.

While I wait for input from Seagate, I have not found anything regarding this online. Has anybody else ever encountered this and fixed it?

 

[bogdanw]

I just got off the phone with Seagate technical support who said once you plug a Mac formatted hard drive into windows, it becomes completely unreadable by a Mac computer.

That’s not true. While Windows can not natively read HFS, it does not automatically destroy the partitions.
Software to read HFS on Windows
HFSExplorer https://catacombae.org/hfsexplorer/
HFS+ for Windows by Paragon https://www.paragon-software.com/home/hfs-windows/

Even if a message was displayed in Windows that the drive needs to be initialized and you wrongly chose to do it, the partitions can still be recovered with software like TestDisk https://www.cgsecurity.org/wiki/TestDisk_Step_By_Step

 

[Tozovac]

That’s not true. While Windows can not natively read HFS, it does not automatically destroy the partitions.
Software to read HFS on Windows
HFSExplorer https://catacombae.org/hfsexplorer/
HFS+ for Windows by Paragon https://www.paragon-software.com/home/hfs-windows/

Even if a message was displayed in Windows that the drive needs to be initialized and you wrongly chose to do it, the partitions can still be recovered with software like TestDisk https://www.cgsecurity.org/wiki/TestDisk_Step_By_Step

Thanks I'll give that a try. I found it questionable that merely connecting a Mac-formatted external drive to Windows 11 would result in non-mountability by a Mac. But he sure keyed in on that when he asked me had I recently connected the drive to a PC. I called the 1-800 number from here:

Contact Us | Seagate US

www.seagate.com

800.732.4283

 

[Tozovac]

Even if a message was displayed in Windows that the drive needs to be initialized and you wrongly chose to do it, the partitions can still be recovered with software like TestDisk https://www.cgsecurity.org/wiki/TestDisk_Step_By_Step

And, there was no message in Windows. Instead, the drive failed to even show up in the Windows file explorer window, though Windows 11 did sound a "ding" noise the moment the drive was connected.

 

[bogdanw]

And, there was no message in Windows. Instead, the drive failed to even show up in the Windows file explorer window, though Windows 11 did sound a "ding" noise the moment the drive was connected.

The ding was for new hardware connected.
The fact that it didn’t show up in Windows Explorer is good and bad.
It’s good because the default message for a HFS drive is to ask you to format it (I’ve just tested in Windows 10). So, if it didn’t show up and didn't display a message, you couldn’t have accidentally formatted the drive.
It’s bad because the cable or the drive might be defective. Try first with another cable.

 

[Tozovac]

The ding was for new hardware connected.
The fact that it didn’t show up in Windows Explorer is good and bad.
It’s good because the default message for a HFS drive is to ask you to format it (I’ve just tested in Windows 10). So, if it didn’t show up and didn't display a message, you couldn’t have accidentally formatted the drive.
It’s bad because the cable or the drive might be defective. Try first with another cable.

Thanks. I tried three cables and none enabled the drive to be recognized by my son‘s windows 11 machine.

Wondering now if it’s worth prying the drive apart and trying the drive in a new enclosure or hot swap type mounting hub?

 

[bogdanw]

Thanks. I tried three cables and none enabled the drive to be recognized by my son‘s windows 11 machine.

Wondering now if it’s worth prying the drive apart and trying the drive in a new enclosure or hot swap type mounting hub?

I think you should keep trying to connect it to your Mac and run First Aid from Disk Utility. In another enclosure, if you have.

If your son has a desktop PC, I suggest connecting the drive directly through an internal SATA connector. In that way you can ensure it’s properly powered and the connection is not mediated by an USB controller.