Kernel-Power Event ID: 41 Category (63)

Hi! I have been having an issue with my computer crashing during gaming sessions or just watching videos. This issue does not occur when simply viewing the web. The issue appears in Event Viewer as Kernel-Power Event ID: 41 Task 63 and states the computer did not shut down properly. I tried looking through many forums on different sites, but I can't find a solution. The reboots began when I got the PC back in July 2014 and thinking the issue was the graphics card and power supply, I had them both replaced. The issue continued even after they were replaced and I really can't figure this out. I would really like to know what is wrong with my computer so I hope someone can help me fix this!

My specs are:
Motherboard: MSI Z1-7641
Processor: AMD FX(tm)-6300 Six-Core Processor (6 CPUs), ~3.5GHz
Memory: 8192MB
Graphics Card: NVIDIA GTX 750Ti 4GB
PSU: Capstone 750W
OS: Windows 8.1