Try running memtest86+, download and copy the .iso file (about 1/2 way down the page) to a USB stick or CD, and boot to that after POST. Let it successfully complete at least 1 complete pass with no errors. If you get errors, test each stick of RAM individually.
Errors happen because of bad RAM or bad RAM settings, including speed (more MHz than the RAM is rated, e.g., 1774MHz vs. 1600MHz, latencies (timings, like 7-7-7-24 vs. 9-9-9-26), or power (Voltage - too low). If you get errors, try setting the RAM to its stock settings - the BIOS settings printed on the stickers.