Computer Crashing to black screen and rebooting

Hey, I just moved my computer over to a new case to fit a new gpu which is the Gigabyte R9 280x OC edition. now 2days later my computer randomly goes to a black screen and restarts it goes to a black screen almost like a power outtage all my usb devices reset.

Here is my HWMonitor Results:

http://imgur.com/Sh0ooly

and my system specs:

OS Name Microsoft Windows 8.1 Pro
Version 6.3.9600 Build 9600
Other OS Description Not Available
OS Manufacturer Microsoft Corporation
System Name LIAMCW-PC
System Manufacturer Gigabyte Technology Co., Ltd.
System Model Z68A-D3-B3
System Type x64-based PC
System SKU
Processor Intel(R) Core(TM) i5-2500K CPU @ 3.30GHz, 3601 Mhz, 4 Core(s), 4 Logical Processor(s)
BIOS Version/Date Award Software International, Inc. F11, 21/03/2012
SMBIOS Version 2.4
Embedded Controller Version 255.255
BIOS Mode Legacy
BaseBoard Manufacturer Gigabyte Technology Co., Ltd.
BaseBoard Model Not Available
BaseBoard Name Base Board
Platform Role Desktop
Secure Boot State Unsupported
PCR7 Configuration Binding Not Possible
Windows Directory C:\WINDOWS
System Directory C:\WINDOWS\system32
Boot Device \Device\HarddiskVolume1
Locale United Kingdom
Hardware Abstraction Layer Version = "6.3.9600.16408"
Username Liamcw-PC\LIAMCW-PC\Liamcw
Time Zone GMT Standard Time
Installed Physical Memory (RAM) 8.00 GB
Total Physical Memory 7.98 GB
Available Physical Memory 5.08 GB
Total Virtual Memory 16.0 GB
Available Virtual Memory 12.5 GB
Page File Space 8.00 GB
Page File C:\pagefile.sys
Hyper-V - VM Monitor Mode Extensions Yes
Hyper-V - Second Level Address Translation Extensions Yes
Hyper-V - Virtualisation Enabled in Firmware Yes
Hyper-V - Data Execution Protection Yes

More stuff about my gpu http://i.imgur.com/jnZSis4.png

I have a coolmaster 700watt psu. The psu is about 3-4 year old now.


I have also done windows memory tests and they didnt find anything. Do you think it could be psu or hdd related?

Also this happened while watching a movie on netflix using google chrome.
I've also done a bios update this didnt help.

**Update**

Just opened my computer checked all connections and made more room for the psu fan on the floor also took off a dust protector made out of plastic which I tested and it held the air from getting in or out so I took it off. The dust protector was for the psu. I will update if the crashing happens again.

**Update**

Crash happened again. Any help? I also just recently when changing over to the new case changed the slots my ram is in.