Hello, so I recently bought some fans for my case and my cpu Its about 5 Cº cooler on idle and under load, so I decided to overclock it even more 
Specs:
A10 7700k 3.4Ghz @ 3.8
Hyperx Fury 1x4 1x8 @ 1600 CL7
Stock CPU and GPU cooler
MSI GTX 750ti
Generic 500w PSU
500GB WD Disk 7200rpm
MOBO: A55BM-A/USB3
So, my CPU was stable for 30 Minutes @ 4.0GHz in a furmark burn test, so I thought it was good, I ran a prime95 for about 2 hours and good. Later on I was making a song in fruity loops and it crashed, WHY DIDNT IT CRASHED WHEN I WAS WATCHING VIDEOS, Im really mad, it was about 3 hours of work, anyways, any solution? My CPU temps under full load don't exceed 60Cº

Specs:
A10 7700k 3.4Ghz @ 3.8
Hyperx Fury 1x4 1x8 @ 1600 CL7
Stock CPU and GPU cooler
MSI GTX 750ti
Generic 500w PSU
500GB WD Disk 7200rpm
MOBO: A55BM-A/USB3
So, my CPU was stable for 30 Minutes @ 4.0GHz in a furmark burn test, so I thought it was good, I ran a prime95 for about 2 hours and good. Later on I was making a song in fruity loops and it crashed, WHY DIDNT IT CRASHED WHEN I WAS WATCHING VIDEOS, Im really mad, it was about 3 hours of work, anyways, any solution? My CPU temps under full load don't exceed 60Cº