Three solutions come to mind:
(1) Newer versions of
File Commander supposedly support >2GB
(2) xcopy (which should work with larger files, assuming large file support is available in the particular version of Warp/eCS you are using)
(3) You can FTP them using Peter Moylan's ftpd, which has large file support enabled.
If you don't have a client that supports larger than 2GB files, you can use a Windows or Linux machine as an intermediary:
(Step 1) With ftpd running on the 1/2TB machine, ftp to a Windows/Linux machine
(Step 2) With ftpd running on the 1TB machine, ftp from the Windows/Linux machine
FAT32 is supposed to be limited to 4GB files, btw.
If you are still running into issues, the problem may be in eCS/Warp's FAT32 support, which may not have >2GB support. If that's the case, there is no way around this other than by someone updating the FAT32 drivers.
Best,
Robert