1. Never ever remove your USB flash drive either you’re not using it or in use; transferring data, saving data, copying, or what so ever. Go to ” Safely Remove Hardware“, stop the drive and when it says that It is safe to remove, you can now remove the drive.
2. If your data were being corrupted, Go to My Computer, Right click the Removable drive, Go to Properties >Tools. Run Error Checking and Scan for errors and fix them. The files that are corrupt or in bad sectors already will not work but at least the new transferred files should work.
3. If Run Error Checking and Scan for errors doesn’t work, make a back up of your data and format your drive. Go to My Computer, Right click the Removable drive, Go to Properties >Tools. Click the Back Up > Choose the file to back up > Choose Destination where to put your back up file.