How to fix USB thumb drive not readable by this computer?

Posted by Vivian to Mac Data Recovery on January 23rd, 2019

My Toshiba 4GB USB thumb drive pops up an error every time I insert it. The error shows as "The disk you inserted was not readable by this computer." When I open Disk Utility, the drive is shown but none of the volumes are readable. I don't want to just toss it, I have some data that I don't want to lose on it. Please help.

Seeing the error message "The disk you inserted was not readable by this computer" is a frustration for most Mac users because by no means can you access data on this disk. Your USB thumb drive may be usable yesterday but suddenly not readable by your computer this morning. And you don't even know what happened and how to fix this annoyance. Don't worry, this article will explain why the USB thumb drive is not readable by this computer and provide 5 feasible solutions for you.

Why the USB thumb drive become unreadable on Mac computer?

Usually, a USB thumb drive is unreadable probably because of the faulty USB port or cable, malfunctioned Mac, and corrupted USB drive, etc. In these causes, drive corruption is the knottiest one, which could result from virus attacks, directory file corruptions, bad sector, and many other reasons.

5 solutions to unreadable USB thumb drives issue on Mac

Solution 1: Reinsert the USB thumb Drive

First of all, you can try to reinsert this USB thumb drive into another USB port, cable, Mac to check if it is a faulty connection that makes your drive unreadable.

Solution 2: Update Drivers on Mac

If the error still exists, you can check if the drivers on your Mac is renewed. Sometimes you need to update the drivers after upgrading your Mac to a new macOS, or your external drives will not be recognized by you Mac if the drivers are outdated.

Soluiton 3: Repair the USB thumb drive via Disk Utility

If the USB thumb drive is not readable by your computer still, then your drive might have some logical errors. Fortunately, Mac offers an inbuilt repair tool called Disk Utility, which can verify and repair minor drive errors.

Step 1: Find Utilities in Applications and choose Disk Utility.

Step 1: Launch Disk Utility and click the USB thumb drive in the left sidebar.

Step 1: Click First Aid to check and repair errors in this drive.

Solution 4: Recover data and erase this USB thumb drive

Your USB thumb drive may still be unreadable even after First Aid, in this case, the file system of this drive could be seriously corrupted. Reformatting can solve the file system corruption issue but at the cost of data erasure. Therefore, you'd better firstly recover data from this unreadable USB thumb drive with Mac data recovery software like iBoysoft Mac Data Recovery.

iBoysoft Mac Data Recovery is a reliable USB data recovery tool for Mac. It can recover data from unreadable/unmountable/unrecognizable/inaccessible USB drives, and recover data from SD cards, external hard drives, memory cards, CF cards, flash drives, etc. The powerful data recovery tool supports data recovery in macOS Catalina/Mojave/High Sierra/Sierra and Mac OS X 10.11/10.10/10.9/10.8/10.7.

Step 1: Download iBoysoft Mac Data Recovery on your Mac, install and launch it.

Step 2: Select the unreadable USB thumb drive and click "Next" to scan for all data on this drive.

 recover data from USB thumb drive - iBoysoft Mac Data Recovery

Step 3: Preview scanning results and choose the files you want to recover.

Step 4: Click "Recover" to get your data back.

After recovering data from the unreadable USB thumb drive, you can either reformat this drive or get a new USB drive.

Solution 5: Ask local data recovery services for help

If these solutions all failed to fix the USB thumb drive not readable issue for you, your drive may have some hardware problems and you need to ask help from local data recovery intuitions.

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