What happens is, after my computer has been turned off all night(this is important). My side fan and my heatsink starts to spin too slow, if not at all. When my OS loads up my computer goes all slow and eventually freezes. What follows is 20mins/6 hours of "disk read errors, windows hang ups". When i finally get back on it's fine for the rest of the day. The strange thing is, if i leave my PC on for a few days without any lengthly turn off there is no problem. Also if i restart my computer or even turn it off and then back on immediately it's fine. It's only if it has been switched off all night.