Computer turned REALLY SLOW after unplugging AC from the wall while ON

Yes I have. Although in the Power Options, I do not know what the Processor Power Management is.

Maximum processor frequency
Setting: 0 MHz

Minimum processor state
Setting: 100%

System cooling policy
Setting: Active

Maximum processor state
Setting: 100%

I know it's solved, but still give me more information on ways to remove this. :)

I finished a clean installation. Although, when I started off new, I downloaded everything and it was all fine! I was happy that it was fine but the day before it started lagging, I changed the power mode to High Performance mode and when I came back, I had the exact same issue. I don't want to keep doing the "Media Creation Tool" way everytime!