Zend certified PHP/Magento developer

games using less cpu after factory reset

I recently factory reset my pc because my games started to lag a bit, and when i reinstalled them, they started using much less cpu than before, im on a i5 with 4 cores. before the reset CSGO would use 50-70% but know it barely uses 10%.
ive looked through power plans and prioritisation settings and nothing is working.
does anyone know whats happened?