when ever i store a word document in my usb and open to check if its is stored properly ,it doesnt gives any error in reading the word document . But when i remove and replug my usb again and again try to read that document it shows erreor that Microsoft word needs some converter to read that file .It is giving this error to this specific documnet while the rest of document in my usb are working well .....what should i do .is there some virus in my USB?if there is how can i remove it?