PC abruptly switches off at random times
I would try to redownload the .iso and try again. It's possible a file in it got corrupt when you were mounting it with the other software.
EDIT: try to pull out some or swap your RAM chips around. Then retry.
CPU: Intel i5 3570k
CPU cooling: Coolermaster Hyper 212 Evo
MOBO:MSI Z77A-GD65 Gaming
RAM:G.Skill RipJaws X Series 8GB(two 4GB)
GPU: MSI Gaming OC GeForce GTX 760 2GB
SSD/HDD:SamSung SSD 120 GB, Seagate 1TB HDD
PSU:Rosewill CAPSTONE-550-M 550W
Case:Corsair Graphite Series 600T Arctic White Steel