You might have to remove an existing GPT partition table from a hard disk when you install another OS like Windows which can't cope with GPT or like in my case, when you want to add an HDD into a
Hard Drive Not Shown on Computer (Windows)
The absence of a hard drive on your system can have multiple reasons of which I want to discuss the most common here: New drives If it's a new hard drive or one that you have just plugged into that