In my external drive, I created a partition for bootcamp

[eresall]

But in "Please select the destination disk" part, the only option it's giving me is what seems like the entire external drive.
It says:
Disk 1: WD easystore 2647

Which seems to be the name of my whole drive? (I have a portion of it named Bootcamp; it's empty and )

Does WintoUSB allow using only a portion of the drive as bootcamp or does it require the whole drive to be dedicated to bootcamp?

Or, since I have only the Bootcamp portion of my drive formatted to MS-DOS, will WintoUSB only affect that part of my drive and leave other partitions alone?

[admin]

But in "Please select the destination disk" part, the only option it's giving me is what seems like the entire external drive.
It says:
Disk 1: WD easystore 2647

Which seems to be the name of my whole drive? (I have a portion of it named Bootcamp; it's empty and )

Does WintoUSB allow using only a portion of the drive as bootcamp or does it require the whole drive to be dedicated to bootcamp?

Or, since I have only the Bootcamp portion of my drive formatted to MS-DOS, will WintoUSB only affect that part of my drive and leave other partitions alone?

If you want to use a custom partition layout, you should select the "Keep the existing partition scheme" option, this option allows you to keep the existing partition structure without format the disk. In such case, you have to manually prepare the required partition, here is the guide for how to manually prepare partitions for portable Windows:
https://www.easyuefi.com/wintousb/resour...to-go.html

[eresall]

If the drive is already formatted in Mac, should it be re-formatted in Windows?
My drive is more than 2TB, so I guess it would not not be BIOS-based (since more than 2TB doesn't work with BIOS) but UEFI-based.

On the website it says:
"Booting UEFI-based computers: Please convert the USB drive to GPT partition scheme and create the EFI system partition (ESP) and boot partition. The EFI system partition must be FAT32 format and the boot partition must be NTFS format."

I read this about EFI but I was kind of confused: https://www.easyuefi.com/wintousb/faq/en...ition.html

There is a single screenshot.
Why is Disk 0 and Disk 1 have same Gigabyte? Is Disk 0 and Disk 1 just one partition?
How do you get to the EFI partition in the first place?

[admin]

In fact, I don’t really understand what you are confused about? Obviously Disk 0 and Disk 1 are different disks, and they have two partitions respectively. In the UEFI BIOS firmware, there will be different boot options that point to ESP partitions on different disks. When you select different boot options, you can start the operating system from different disks.