kruiz means by the fan slowing down that hes previously applied the fan speed to 100% in the nvidia drivers settings, the fan will run at normal speed 50% till you manauly apply it at 100%
the reason why his fan speed jumps from 100% back down 50% when hes in rfactor beats me, i would need a look at it myself, it could be a bug with windows home
the heatsink on kruiz's set up must be one of the worst ones ever made, the cpu has the heat sink attached but no fan, the fans attached to the case and draws air through the green duct to cool it, third party heatskinks are out the window as its been designed for dell parts too
a new case won't solve the problems as its a bad lay out with the dell motherboard with all parts being close together, i doubt dell motherboards would even fit in another case as they make the components to suit themselves
my mate has the exact same pc as kruiz's and we had the same problem till we made some custom cooling for him, same as pedz's idea with a hole on the side of the case at graphics card with a tumble drier hose attached to the air vent on my mates wall which gets the cooler air from outside
kruiz's dillema is he is not near any wall vents or window's (young ofenders institute) so i sudgested he buy an air chiller like tosh uses which will give him the lower temps he needs rather than blowing in the hot air from his room