Unless the drive manufacturer provides some sort of "extended capacity manager" like Seagate once upon a time did, or have some sort of chip or brain in the external drive's firmware, chances are you will NOT be able to detect or use any drive over 2 TB in capacity.
I had purchased an eternal seagate hard drive that was 3TB in size and guaranteed it could be viewed from any 32-bit OS, and it worked. I suspect in the case of the external drive it was due to a controller built into the drive dock of the external enclosure.
I have a newer Seagate HDD that's got 8TB of space, and my XP 32-bit cannot view it. My XP 64 can.