As of revision 46805 IDLE fails silently on launch. If
launched from a command prompt the following output is
seen.

D:\Python24\Lib\idlelib>python idle.py
Traceback (most recent call last):
  File "idle.py", line 2, in ?
    import idlelib.PyShell
  File "D:\Python24\lib\idlelib\PyShell.py", line 27, in ?
    from EditorWindow import EditorWindow, fixwordbreaks
  File "D:\Python24\lib\idlelib\EditorWindow.py", line
42, in ?
    class EditorWindow(object):
  File "D:\Python24\lib\idlelib\EditorWindow.py", line
47, in EditorWindow
    import Bindings
  File "D:\Python24\lib\idlelib\Bindings.py", line 109,
in ?
    default_keydefs = idleConf.GetCurrentKeySet()
  File "D:\Python24\lib\idlelib\configHandler.py", line
499, in GetCurrentKeySet

    result = self.GetKeySet(self.CurrentKeys())
  File "D:\Python24\lib\idlelib\configHandler.py", line
519, in GetKeySet
    activeExtns=self.GetExtensions(active_only=1)
  File "D:\Python24\lib\idlelib\configHandler.py", line
377, in GetExtensions
    extns=self.RemoveKeyBindNames(
  File "D:\Python24\lib\idlelib\configHandler.py", line
410, in RemoveKeyBindNames
    if name.endswith(('_bindings', '_cfgBindings')):
TypeError: expected a character buffer object

Logged In: YES 
user_id=149084

It appears that you are running a mixed system
on XP: Python 2.4 and IDLE from the repository.

At 46805 IDLE was modified to reflect new syntax:

"Make use of new str.startswith/endswith semantics.
Occurences in email and compiler were ignored due to 
backwards compat requirements."

The change is:

http://svn.python.org/view/python/trunk/Lib/idlelib/
configHandler.py?rev=46805&r1=38395&r2=46805

My suggestion would be to move to 2.5b2, now
available.  Otherwise, modify your configHandler.py
source to revert this change locally.