It all started 3-4 months back. When I boot up my laptop, after its idle for some time, my GPU usage shoots up to 99%. Before 4 months all games that I installed on it were working very well on medium and high settings with full 1080p resolution. But from the time this problem started all games have started lagging too much, at some times the game is unplayable.I uninstalled many games leaving just two on my laptop I tried to run both the games on lowest settings and resolution possible but the lag wouldn't go away. Earlier I was able to play Far Cry Primal and Watch Dogs on high setting and 1080p but now even Far Cry 3 lags on lowest settings and resolution. I have properly cleaned my PC of all unwanted files and have run de-fragmentation and any types of driver updates or disabling startup items but all in vain. I don't know what to do, please help me.