I originally formatted a Western Digital Passport drive on a Mac for a SuperDuper! clone backup. But later I needed to use the drive on a Windows system. More specifically I needed to use the drive as attached router storage. The router would refuse to play nicely with any drive containing an EFI partition. Formatting the drive in Windows 8 using Administrative Tools left the EFI pattition intact. I found the solution was to dig into the Command Prompt and use a disk utility “diskpart” that ships with Windows to “clean” the drive.
Diskpart can be used to wipe a drive clean of all partitions. It will wipe EVERYTHING and require you to format the drive in Windows afterwards to a valid filesystem such as NTFS or XFAT before you can use it.
Here are the steps I successfully followed: