Since we have no idea what you're actually trying to do in octave, it's hard to give you any advice to make it run faster. Since you are running on Windows I assume you've done the usual things like close all other programs. Have you checked your power settings to make sure they haven't stepped back your CPU speed? If you hold down Windows key and tap X it will bring up a menu that includes the mobility center. That has shortcuts two power that are mainly used if you're running on a laptop. If you are in a power saver or balanced mode, you may be running with reduced CPU speed. Make sure it says high performance or something equivalent.
That said it's entirely possible you're running an infinite loop inside of octave and you may be waiting a while