
Hey Faraz,
I apologize for the delay in getting to your thread. First of all, I would like to recommend that in the future, you do not purchase things like Flash drives second hand. You are putting yourself in a difficult position when they do not work, and purchasing them new is so inexpensive these days. So enough lecturing, let's see if we can help you resolve this.
Have you done any dianostics on this flash to make sure that the drive isn't corrupted?
Reformat the flash again, and then run chkdsk /r to check for bad sectors. That should tell you if in fact you bought a lemon.
Also, check in Device Manager, and see if there is either a red X or a yellow exclamation point.
Looking forward to your reply,
TTFN
LGW