Mymachine runs fine most of the time. However, at times it runs extremely slowly so that the mouse judders ans and sounds are broken. Task manger shows 40-50% CPU usage but nothing in the proceses is using that (I have all user thing ticked). I wonder if this is an over-heating problem as I once saw a fleeting boot-up message about a "previous fan error". I can hear a fan though! The room is cool. So, would over-heating cause this? If so how can I tell if it is in fact this? Cheers!