GA-H61MA-D2V-USB3 Random reboots

[tuc tuc]

The PC I built recently has developed a problem where it randomly reboots on its own with no warning, any ideas what this could be? I seem to remember reading on here some issue with this happening to others, but cannot find now.

Also, when I installed new software & had to restart it would retart twice before booting to windows, is this connected?

PC spec
GA-H61MA-D2V-USB3
4gb corsair ddr3 2sticks
Intel G620

[Lsdmeasap]

Please update to the latest BIOS, using Qflash or DOS.  Then once the flash is done enter the BIOS and load optimized defaults, then save/apply/reboot BACK to the BIOS.   Once in the BIOS again set your SATA settings, and all other changes you need to make such as memory voltage, ect.  Then save/apply/reboot to windows.   

Then shut reboot from windows and update the backup BIOS using the following guide.   You may need to use a PS/2 keyboard, or USB to PS/2 adapter
http://gigabytedaily.blogspot.com/2011/02/video-guide-how-to-update-your-backup.html

I would link you to the latest BIOS page, but I cannot right now as I can't find that model listed anywhere at Gigabyte's site.   Are you sure that is the exact model name?   Can you please post a screenshot of CPU-z Mainboard tab so we can verify, thanks!
http://www.cpuid.com/cpuz.php

If it's just GA-H61MA-D2V model, then your latest BIOS is here, but there is only one listed (F3) so you may already be using it
http://www.gigabyte.com/products/product-page.aspx?pid=4090#bios

Can you please test your memory, one stick at a time for at least 5-10 full passes or overnight, using this latest version of Memtest86+
http://www.memtest.org/#downiso