I've had a problem with freezing when left on for long periods from the beginning. The problem took around  two weeks to show. I contacted support, they had me removing memory two sticks at a time to see if problem returned and it did, but over a about eight weeks or so. It didn't matter which sticks were in it still froze. I decided to buy two new matched memory sticks and methodically numbered and swapped them out. Considering the two or so week failure interval this has gone on for over a year. I just replaced all memory with all new matched memory It failed the other day. I had the exact same programs/hardware on a much lesser laptop for 4 years with no problem prior, in fact it still works to this day if I swap it out.