So I upgraded to W10 last week and came along this problem. Every time i use my laptop it randomly switches its power setting by itself from balanced to high performance like once every hour. When it does that it also shows the start menu. I was baffled at first. My balanced brightness is set to 50% when running on batteries but after a few moments it starts to change to 100% brightness and realized it has already changed to High Performance. The same thing happens when i plug my pc in.

I have to set it back manually to Balanced every now and then and its really annoying, especially when the start menu pops up while i am using programs and playing games. Also, when i turn off the display for an overnight download, it turns on by itself anytime during the night when it changes power setting... waking me up. If anyone could help...