Hello and welcome to PC Help Forum!!
Let's see if we can turn those reboots into some useful messages.
Right click
MY COMPUTER, choose
PROPERTIES, choose
ADVANCED, choose the
SETTINGS button in the
Startup And RECOVERY section, and uncheck
AUTOMATICALLY RESTART
Now reboot. This should result in the
BSOD error, either right away or later on when it normally would restart.
When you see it, tell me the STOP ERROR and any parameters.
In addition, for your
RAM sticks, I have a program which has turned out to be more reliable than Memtest.
Download
Stress Prime
After you download it, double-click on it (which opens the CAB that it is in) and drag the program to your desktop. Now you can run it. Click on the drop-down box at the top and select
Large, in-place FFTs - stress RAM and click
Start
If it detects a fatal error, it will stop automatically and then report it. Let me know if that happens.
Otherwise, stop the scan after about 30 minutes, and then in the window at the bottom, it will say if any errors/warnings were detected. Let me know what it says.