IDLE has suddenly become FAWLTY - so should I be hitting it with a big stick, or what?

[pypythotho]

'python -m idlelib' gave me information about a file, ntpath.py, that I've edited before with notepad++. This file has been rewritten with a tab instead of 4 paces. The command suggested by Terry displayed an explicit message about wrong indentation. This error fixed, IDLE run again like a charm.