SORT.EXE and Windows NT

A ‘out of memory’ exception is received when sorting large files. I need to sort a 700MB+ file and when I tried to use the following command, I receive an ‘out of memory’exception.
sort < input_file > output_file

The server that I am running this sort on contains enough memory (4GB). What are the limitations of the ‘Sort’ program under Windows NT ? I am able to execute the sort with the same size file successfully under Windows 2000.

Thanks