Flash drive not working

KillianG wrote:

Every time I try to plug in my USB Flash drive, I get the same error The disk you attached was not readable by this computer.

Erase and reformat a storage device in Disk Utility on Mac

https://support.apple.com/guide/disk-utility/erase-and-reformat-a-storage-device-dskutl14079/19.0/mac/10.15

KillianG wrote:

It was formatted in ExFat, I thought I said that! Sorry for missing that too. Thanks for your help by the way.

See if there is anything here:

exFAT drive won't mount on Mac, fine on Windows...

https://discussions.apple.com/thread/251744050

KillianG wrote:

But this seems to wipe all of the data, I need the data that was on the drive. It was readable by my old Windows laptop (I no longer can use). Is their a way not to fully erase it?

With this new information provided—

i suspect Windows format is NTFS. Which is not native to the macOS however In this to r/w this format you need third party software like:

tuxera

paragon

there are others.