On Windows IDLE's working directory is Python's install directory, e.g., C:\Python34. ISTM that this is the wrong directory for 99% of general users and for 100% of beginners since this is _not_ the directory where people should save their own .py files (unless they are experts, in which case they know better and won't anyway).

I think that IDLE should start out in the user's home directory (ideally on all platforms).