usbs

If any of you smart computer savvy people could help me out, I'd greatly appreciate it. My USB flash drive isn't being recognized. I know it's the flash drive and not my computer because I have tried it on several different computers and another flash drive I have works on those computers...

I was using a 512 MB flash drive that I'd gotten free as part of a Staples promotional offer. It was working fine and I was using it to back up my schoolwork and writing projects-- up until just yesterday. All of a sudden, when I tried to copy files to it, Windows Explorer gave me the message...