I am crazy. I have 2 USB Hard Disk, one (A) was bought about half a year ago, the other (B) was bought two months ago. From last week on, A cannot be read in my PC but B can, I tried serveral times and the result was the same. I thought maybe A is broken, but A has at most all my data of job, so I asked my colleage for help. When he inserted A in his PC, oh my god, it can be read. what a surprice! Then I tried to insert it in my pc again, there was still no response. what should I do? Anybody can help me?