Re: Format External Hard drive.
Of course. You'll loose your data though. If you are formatting in Windows, I recommend MiniTool Partition Wizard Free. The best idea is to format to FAT32 to ensure compatibility with everything.
You probably don't even need to do this, since hard drives are formatted to FAT32 by default by manufacturers so you don't have any issues using it on any computer.
"Perception without comprehension is a dangerous combination."