If no computers see the drive when you connect it—even in the Disk Management window—the USB drive itself is likely dead. To read a drive like this one, you can either connect it to the Mac or Linux PC it was made on and copy your files off of it onto another drive, or you can use software that lets you read Mac-formatted drives or Linux file systems in Windows. If the drive appears in Disk Management and you see one or more partitions on the drive—with a blue bar along the top—it may not appear in File Explorer because it needs to be assigned drive letters.