Using the suprocess module from with IDLE or PyWindows,
it appears that calls GetStdHandle (STD_<???>_HANDLE)
returns None, which causes an error.  (All appears fine
on Linux, the standard Python command-line, and ipython.)

For example:
>>> import subprocess
>>> p = subprocess.Popen("dir", stdout=subprocess.PIPE)

Traceback (most recent call last):
  File "<pyshell#49>", line 1, in -toplevel-
    p = subprocess.Popen("dir", stdout=subprocess.PIPE)
  File "C:\Python24\lib\subprocess.py", line 545, in
__init__
    (p2cread, p2cwrite,
  File "C:\Python24\lib\subprocess.py", line 605, in
_get_handles
    p2cread = self._make_inheritable(p2cread)
  File "C:\Python24\lib\subprocess.py", line 646, in
_make_inheritable
    DUPLICATE_SAME_ACCESS)
TypeError: an integer is required

The error originates in the mswindows implementation of
_get_handles.  You need to set one of stdin, stdout, or
strerr because the first line in the method is:
if stdin == None and stdout == None and stderr == None:
...return (None, None, None, None, None, None)

I added "if not handle: return GetCurrentProcess()" to
_make_inheritable() as below and it worked.  Of course,
I really do not know what is going on, so I am letting
go now...

def _make_inheritable(self, handle):
..."""Return a duplicate of handle, which is inheritable"""
...if not handle: return GetCurrentProcess()
...return DuplicateHandle(GetCurrentProcess(), handle,
....................................GetCurrentProcess(),
0, 1,
....................................DUPLICATE_SAME_ACCESS)