Firmware updater not working after unpluging from computer..

Have a Clip Sport, current ver 1.39.  Downloaded new ver 1.43 to my computer, Windows 7, 64 bit.  Transfered the hex file from Downloads to the root directory.  After disconnecting from the computer,  it is supposed to update to the new verson, but is not doing so.  No SD card, and the memory is not near full.  Any suggestions?