Originally Posted by cyrnel

Fight the problem. Don't create others.

For whatever reason Intel active monitor failed to correctly identify your processor's target core voltage. The first pictures show it was confused about the target, yet correctly reported the actual operating voltage, which was fine. This is why it posted the errors. It was wrong. The second picture correctly shows the target core voltage and the same operating voltage as the first post. Nothing changed other than the behavior of your monitoring software.

From here it looks like a temporary software problem. Active monitor was referencing the wrong value for your processor. (Any chance you were logged in as a different user?) If you see the error report again then it's time to look for something in common and troubleshoot. What was the last thing you did before it happened? What cleared it?

P4 Prescott cores run between 1.25 and 1.55V. Northwood 1.525-1.6V. A 3.1V core Pentium would be very old.