I'm trying to clear the history for october & november in windows 7. Every time i try nothing happens!!!

Where N3 are you talking about browser and if so which one?

Firefox

Not sure N3 as I no longer use that one but out of curiosity, why do you want to empty the history? I just did it in Pale Moon on this Windows 8.1 pc and it emptied fine. Not sure why it wouldn't.