When the PerfMon started, many power saving features don't work. The display is constantly working, laptop and PC will never go into sleep mode, the hard drive always keeps spinning. For PC is not critical, but for a laptop that is running on battery is not very good. Run as administrator doesn't help.
you are not the first stating this issue about this program. I use it everyday in all my PC without any particolar configuration and they work as expected (also go to sleep mode) The program does nothing special, it only calls Windows functions for getting performance data
I have used this program two years ago. Because of this issue I had to stop using it. Now I have a completely different PC and a new laptop, but all remained the same. I can't find a reason why my PC and laptop doesn't go into power-saving modes when perfmon running.