Large FAT32 external harddrives and Windows 10 issue

fat32 error is common known as looping fat

jmjacobson said:

And, the items on this drive are irreplaceable, so converting in not an option.

I've run into that issue, one I recall vividly was a companies books were lost. After trying I could only recommend they use a company that specialized in recovery, there's many but the one I used is called Ontrack. Due to the importance of the data the client was okay with it, sent the drive, got an estimate for just the diagnostic, got approval of the client, they got their data and drive. The estimate applied to the against the full cost. Client got a portable drive and learned about backups, I got paid for their learning.

Bree made a good comment in post #9

You should look at tidying up Disk 1 in your first screenshot. The partitions look like an O/S or the remains thereof- Disk 0 seems to be your actual O/S.

As Pentagon commented, given the problems with KB5034441 regarding the size of a Recovery partition (250Mb free space required), that your Recovery partition is only 505Mb is surprising. Typically 1GB is now required for that update. (MS is said to be working on a fix).

dalchina said:

As Pentagon commented, given the problems with KB5034441 regarding the size of a Recovery partition (250Mb free space required).... Typically 1GB is now required for that update. (MS is said to be working on a fix).

With all my machines (including VMs) I have had a lot of practice at getting KB5034441 to install.
By trial and error I have found that a 680MB recovery partition is the absolute minimum required for a successful update.

@jmjacobson

Check your external disks on another working system.( As dalchina pointed out the screenshot posted by you shows the disk was a system disk at some point. . This can give wrong results. Test another external drive which was not a system disk at anytime before and check on another working PC. )

Post the screenshots of Windows Disk Management and MiniTool Partition Wizard as you did in the first post. This will enable the system experts here decide whether indeed your Lenova has a faulty installation after the Reset and suggest remedial measures...

Please tell us the story of this drives.
They have a large (200M) EFI partition so it was once a boot able drive. Was a Windows OS or a Linux OS?
I would say that the partition is ext4 formatted (Linux) and windows don't recognize it.
- How to read ext4 partitions on Windows -