never used memtest, so i'm not sure if its command line like a tool from a CD or GUI whatever a GUI is gonna try and use more memory. Just another option
Your temps and voltages look OK. Your CPU is really chilly, do you have Cool & Quiet enabled in the bios? I would disable it and see if it helps to stabilize the system.
I would try to run memtest again now that it's more stable. Run at least 2 passes if you can.
Bad news. More blue screens. A lot of my startup/service programs give an error message on startup. Blue screens happen pretty much whenever I try to move/delete a file or something like that.
Couldn't find anything about Cool & Quiet in the bios.
Tried running another Memtest - don't think there were any errors, but there was no report after the reboot like there should be.