How to Repair a USB Flash Drive That Is Corrupt

Removing a USB flash drive from a computer's USB port before it has been properly unmounted can corrupt the file structure, rendering the data unreadable. Repair the corrupted USB flash drive using software that comes with either your Mac or Windows operating system. The procedures for repairing the corruption, while dissimilar between operating systems, repair the file structure so that the USB flash drive can be used again.

Repair USB Flash Drive in a Mac

Insert the USB flash drive into a USB port on the Mac. Double-click the Disk Utility program’s icon to launch it--the program is inside of the “Utilities” folder that is inside of the “Applications” folder.

Click the icon of the USB flash drive that is in the left column of the Disk Utility program’s main screen. Click the “First Aid” tab at the top of the program’s main screen.

Click the "Repair Disk” button below the “First Aid” tab. Wait as series of lines scroll down the center of the window. Quit the Disk Utility program when the lines are no longer scrolling.

Drag the icon of the USB flash drive that can now be seen on the desktop to the Trash. Remove the USB flash drive from the USB port of the Mac.

Repair USB Flash Drive in Windows

Insert the USB flash drive into a USB port on a Windows PC.

Right-click the icon of the USB flash drive in File Explorer and select "Properties” from the pop-up window that appears.

Click the “Tools” tab at the top of the Properties window and then click the “Rebuild” button on the window. If you don't see a Rebuild button, click the "Check" button instead, then click the "Scan and Repair" option.

Right-click the icon of the USB flash drive when the repair is complete and select "Eject." You may now safely remove the USB flash drive from the USB port of the PC.