Not sure what error 14 is but it sounds like you messed something up when you swapped the drive. You didn't specify the DVR you have but one thing that can cause a problem is the ribbon cable to the front panel. Make sure it is fully seated and then plug in the DVR again. In older machines this was a nightmare of a problem. As for formatting the drive, don't think you need to do that, should happen automatically if you can get the machine up. If you do get the machine to power up again and the drive doesn't format, you should remove the partitions from the drive and then pop it back in. There is a way to force a format as well but I don't recall how.