I really tried to find something in the Speccy but the Seagate is missing so I can't point out one of the usual there. Moving on as I will dismiss that as you are writing the Speccy is the configuration that crashes.
1. The Speccy is really clean.
2. There is this one thing that lines up with your memory testing above. Actually two things.
2a. The RAM is reporting as UNKNOWN.
2b. The memory speed looks to be below its pay grade. That is, it appears to be at 1066MHz and there's a XMP PROFILE in the sticks at much higher.
More about this area. Not only those problems but the failure you had in memory testing so this is the only area that is poking up like a nail on a sun deck.
1. Try XMP.
2. Try just your new sticks.
3. Check that the sticks are in the right slots for when there are just two.
4. Ask the motherboard maker if these RAM sticks are supported.