|Simple answer is to buy a new one if you have also tested it in another system. If works in other system then your issue is your system not usb flash drive.|
Second choice is to use linux to fix it if possible. Linux or live linux cd offer more access to such devices.
"Best Practices", Event viewer, host file, perfmon, antivirus, anti-spyware, Live CD's, backups, are in my top 10