I got some files from a known friend in my USB flash drive. It was working fine when the files were copied to flash drive but it failed to open when I plugged into my laptop. System threw an error as ‘The File or Directory is Corrupted and Unreadable’. I was able to use one of the options (chkdsk /f <drive letter>:) suggested in the below website and one more website.
After running chkdsk, I got Access Denied error. I gave Everyone read permission under security tab based on some suggestion from one of the articles in internet. This resolved the error. I was able to successfully remove the flash drive. When I plugged in again, it showed a warning message that we have to scan and fix the errors. I did it and it resolved most of the errors faced in that USB flash drive.
I have formatted this USB flash drive and tried accessing in another laptop. It didn’t recognize. Then I went to disk management and assigned a drive letter. It started showing again.
I referred this webpage for solving unrecognized flash drive issue http://www.tomshardware.com/answers/id-2117033/flash-drive-showing-computer.html