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If you haven't already, install software like
Whocrashed or Nirsoft's
Bluescreenview (it is safe even if your antivirus flags it as infected - Nirsoft stuff sometimes flags because of the toolkit they use to build some of their software). Also, go to the start menu and in the run box type "View Advanced System Settings" without the quotes and hit enter. Under the Startup and Recovery section, hit the Settings button. Make sure that Windows is set to save kernel memory dumps.
If these options are already set, Whocrashed or Bluescreenview will allow you to load the dump files to see what is crashing.
It also wouldn't hurt to download and burn a bootable MEMTEST86+ ISO to test your memory modules one at a time ("Windows Explorer stopped responding" always immediately makes me suspect file system corruption, which can begin with a bad memory module more times than not).
If you don't have any monitoring software installed (such as Speedfan or HWMonitor), do so as this will allow you to keep an eye on your CPU and GPU temps to see if anything is out of wack there.