But you know better and you won't be doing that utterly irresponsible thing, right?
Windows will refuse to format a FAT32 drive that large. Use guiformat as a workaround. Download it here:
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ExFAT won't work with 2000 at all, though? But dual-booting Windows NT 4.0 and Windows 2000 should be possible as long as you keep partitions separate. Running multiple versions of Windows from a single partition hasn't been a thing since the DOS days, since Windows itself used to be an MS-DOS application to a certain extent.