d:\oracle\ora92\bin> orastack oracle.exe 500000

D:\oracle\ora92\bin>orastack

        The ORASTACK utility was created to allow users to modify
        the amount of stack that's reserved and/or committed by
        each thread in the Oracle Server.  By running ORASTACK on
        certain .exe files, the headers of these executables are patched
        to reflect the settings specified.  Typically, changing the
        commit size of each thread's stack is not necessary, since NT
        will commit more stack as needed.  However, decreasing each
        thread's reserved size may be necessary since this size comes
        out of the Oracle Server's 2 gigabyte address space. When
        thousands of connections or a large SGA are in use, running
        out of address space in the Oracle server process [although
        still having available physical memory in the machine] is a
        possibility.