Windows no longer recognises external disk as NTFS

I've got an external hard disk which I was using to back up two computers. The last time I used it it was recognised properly as containing an NTFS volume by both computers (both running Windows 10). However this time it is no longer recognised properly by either of the two computers I have tried to connect it to (including one of the ones it worked with last time). Disk manager sees it as containing a "healthy" volume, but not an NTFS one. What could be causing this and what can I do about it? The most important thing for me is to know whether or not the drive can be relied upon for future backups.

I would see what this program says about it:
Free Partition Recovery Tool | MiniTool Software Solution

I've been running that recovery utility for a little while and it has only found 105 files. It stopped finding new files after the first few seconds it was running. So I guess it's not looking good for recovering that partition, but that's not my main concern. What I really need to know is whether the disk hardware is in trouble, or whether I'm OK to keep using it once I've replaced the corrupt partition with a new one. I found a utility that should enable me to get at the S.M.A.R.T. data, but I get the message "SMART status not supported", so I'm really in the dark about the physical health of the disk.

I ran Seagate's Seatools and quickly found that the drive has indeed failed. So there's my answer!

ricecrispies said:

What I really need to know is whether the disk hardware is in trouble, or whether I'm OK to keep using it once I've replaced the corrupt partition with a new one. I found a utility that should enable me to get at the S.M.A.R.T. data, but I get the message "SMART status not supported", so I'm really in the dark about the physical health of the disk.

See what CrystalDiskInfo can tell you. I prefer using the Portable App version....
CrystalDiskInfo Portable | PortableApps.com - Portable software for USB, portable and cloud drives

It could just be that the partition and the data it contains is intact, it's just the partition ID (that tells the system the format) that has been lost. You can set the ID to 0x07 (for NTFS) using Diskpart from an admin command prompt.



If instead the volume is listed as offline, you need to assign it a drive letter - either using Diskpart or Disk Management.

Many thanks for the detailed answer. In this case, as I said in my earlier comment that I must have posted as you were writing, I discovered Seagate's Seatools and was able to determine quickly by using them that the drive is indeed physically broken.