I would test one stick at a time, and I'd let it run for more than 2 passes, at least the full range. I'd also set Windows so that it goes to the BSOD rather than reboots, so that you can see the error code. I'd also make certain that if the memory was auto-set by the BIOS that it doesn't have fubar'd settings, which happens. After that you want to make sure that your BIOS and all firmwares are updated. If that all checks out, then you'll have to start a trial-and-error process on the hardware.