The steps you need to carefully take next.
Don’t format the drive.
Formatting will erase whatever’s on the hard drive, or at least make it much more difficult to recover your data.
I do have suggestions about what to do next.
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Drive Shows as Not Formatted
- “Unformatted” means critical information could not be read.
- This can sometimes be due to file system incompatibilities.
- Rule out hardware issues by trying another computer and possibly a different external enclosure.
- Data recovery tools may help if the hardware all seems to be working.
- Backing up would have made this a non-issue.
When the system indicates a drive is unformatted, that means the system attempted to read the master boot record, partition table, or other overhead information on the drive, and got a result other than the expected data.
In most cases, this means the overhead data on the disk has likely been overwritten or otherwise damaged.
Less commonly, it can also be the result of a hardware failure, either in the disk itself or the circuitry connecting that disk to your computer.
Hardware problems are the easiest to rule out.
There is one software issue that’s worth mentioning before we diagnose hardware, and that’s file systems. Specifically, the fact that while Windows will recognize hard disks formatted by other Windows machines, hard disks formatted on Mac and Linux machines will appear as unformatted when connected to a PC.
Windows generally uses NTFS, or variations of the FAT file system, as disk formats. Mac and Linux machines tend to use different formats by default which are not readable by Windows.
If you are in a situation where you need interoperability, using exFAT, or even NTFS, is generally the most cross-platform compatible.
If you have information on a Mac or Linux formatted hard drive (or thumbdrive) you’ll either need to copy the data to your PC some other way, or, on your Mac or Linux machine, copy it to a disk formatted using a PC-compatible filesystem.
Try another machine
If you have another computer available, plug the external drive into that and see if it is properly recognized.
If it is, then:
- You have access to your data. Back it up now!
- You know there’s an issue with the first computer that needs to be addressed.
Verify the external enclosure
Because you indicated you placed your former internal drive into an external enclosure, I’m suspicious there’s a problem with the assembly.
A working USB interface improperly connected to a hard drive could appear as an unformatted drive.
I’d make absolutely certain that the drive was properly connected to the interface card in that external enclosure. Double- and triple-check that all of the assembly instructions were followed and that the drive is attached correctly.
If you have another hard disk that you know is functioning correctly, I’d be tempted to place it in the enclosure and try it. If it works, then you know you have a problem with the first hard disk (which we’ll look into next). If the substitute disk fails, then you know there’s either a problem with the enclosure itself, its circuitry, or the connection to your PC.
If everything seems to be connected and working properly, but your drive still shows as unformatted, then the disk is compromised and it’s time to haul out the data recovery software.
Piriform (the company that makes CCleaner) also puts out a free tool called Recuva. Among other features, they state, “Even if you’ve formatted a drive so that it looks blank, Recuva can still find your files on it.”
Naturally, no one can guarantee complete recovery, but it’s a place to start.
Another tool to consider is GetDataBack. It’s not free, but the demo version should allow you to determine if the utility will be able to recover anything. If so, the tool might be worth it. From their feature list: “GetDataBack will recover your data if the hard drive’s partition table, boot record, FAT/MFT or root directory are lost or damaged …”
This all would be moot if…
I’d be remiss in my job if I didn’t point out that none of this would matter — or at least it wouldn’t matter nearly as much — if you had backed up the contents of that drive.
Remember the rule of thumb: if it’s only in one place, it’s not backed up.
Hard drives fail, often without warning. That can result in complete data loss.
Whether or not you recover your data this time, resolve to put a backup strategy into place so the next time there’s an issue (and please trust me, there will be a next time) the solution is simple: just restore your most recent backup.