The test program Larry provided does not appear to function as intended on Windows, and runs without either producing error messages or requiring interactive input. Here's a typical output, in this case from Python 3.1 on Vista:

C:\Users\sholden\Documents\issue7839>\python31\python test_subprocess.py
Testing with shell= True and array= True
  ** This is the one that runs an interactive shell.
  ** You should press Ctrl-D.
        Output:
        [] Python 3.1.1
Testing with shell= True and array= False
        Output:
        [] Python 3.1.1
Testing with shell= False and array= True
        Output:
        [] Python 3.1.1
Testing with shell= False and array= False
        Output:
        [] Python 3.1.1

The same behavior was observed on 2.6 and 2.5.2.

[I also removed "Christophe Simonis" from the nosy list as the tracker was complaining that there was no such user].