Some hardware tests to run.



Hard drive(s):
Pick one for your HDD brand or use Seatools.
7 Free Hard Drive Testing Software Tools



RAM (memory):
This will require memtest on a bootable CD or USB stick.
RAM - Test with Memtest86+

Use only identical RAM modules, some boards don't take kindly to different brands and types. Memtest will take several hours with 16GB, be patient, my PC takes 2 hours per pass for all 16GB.