When you set an under volt, does it show up in the monitoring table in the top left corner of the FIVR window.
In the lower right corner of the FIVR window, ThrottleStop has a safety feature. What is that set to?
ThrottleStop has to be run each time your computer starts up so it can apply the undervolt. It should also remain running so when you enter and resume from sleep mode, it can re-apply your undervolt. If ThrottleStop is not running, it can not manage your CPU voltage for you.
Here is a guide so you can add ThrottleStop to your Windows startup sequence using the Task Scheduler.http://forum.notebookreview.com/threads/the-throttlestop-guide.531329/#post-6865107