So let's it interpret this way:
range(1, 300000000) consumes more and more memory, and causes the system
to hang.
When python.exe is in a console, you have the ability to close the
window and kill the process.
When using Idle, the interpreter cannot be killed so easily: I suppose
you closed the main windows, but this did not kill the subprocess used
to run commands.

BTW1: did you try xrange(1, 30000000)

BTW2: msg65177 is not a pseudo... it's the message ID in the bug tracker ;-)