Custom Build BSOD after two fresh W7 Installs

Installed the new heat sink. It is really nice and fit perfectly. I followed the instructions as outlined in the Artic 5 pdf you provided with the single line oriented the same way noting the PIN 1 Triangle marker on the CPU. I am running the Prime 95 Tests again and now the cores are reading from 64 to 68. I would have thought there would be better temp control to keep it below 40 but it is improved.

OK, now while II am typing I am seeing 90 degrees.

So I cleaned off the old thermal paste with a pre wet alcohol swab so it was clean. I did not touch the CPU to make sure it was clean. I also did not touch the heat sink after removing the protective plastic where it interfaces with the CPU.

Temperatures have now dropped to 67-72. So maybe this is ok? Maybe the thermal paste will improve over time as noted in the Artic 5 document?

I am diabetic so I have a large supply of individually wrapped flat cotton sheets pre-moistened with alcohol. These were lot loose cotton balls dipped in alcohol. I used three swabs to make sure all of the old paste was removed. when it dried, I used a can of air to ensure no additional dust settled. I have built systems before (three) but have never replaced a an installed heat sink before. One of the other systems I built also has a high CPU problem. Is that normal for stock heat sinks or am I installing them wrong?

The Prme95 has now been running for 1 hour and 28 minutes. No failures. I assume your comment that I don't have to test the CPU temp means I can stop Prime95.

I have updated my system specs

Ambient Temp is approx 68 degrees F, that is what my thermostat is set to.

So is there a good chance the CPU temp was the root cause for my BSOD and 0X124 error?

Are there other tests to run or is it time to put the system together and give back to my daughter and see if that has resolved her problem?

OK, great. I do really appreciate all of this help. You guys are great! I will keep this thread as unsolved until we have confirmed stability.

Since I am dealing with thermal problems, I should also mention I haven't seen the case fans turn on since starting this testing in January 2016. Both sides have been removed with outside temp around 68 deg F. Maybe they have not has a need to turn on due to low temperatures, but would be nice if there was some software that I could use to manually turn on to confirm they are connected to the mother board correctly.

Pauly / Layback Bear

It has been a little over a week with no BSOD. Thanks so much for your help. It is much appreciated. You guys are many more times helpful than support from PC Component manufactures and allow novice PC builders to successfully build a stable system. I have also learned a lot from you guys. Thanks again.