New build using MSI H87M-G43 and MSI N660-2GD5/OC regular BSODs

So my son and I built a new PC:

i5-4670k
MSI H87M-G43
MSI N660-2GD5/OC
CORSAIR 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600 CMV8GX3M2A1600C11
Samsung SSD 840 PRO Series 120GB
Seagate Barracuda ST500DM002 500GB
Windows 8.1

We've been getting BSODs pretty...