Hey, Blizz,
Unfortunately, because I seen something *very* similar to
your issue, with the issue you are having, even if it goes away for some time, that crashing, including *even* if you didn't change *any* software, including occasional explorer.exe crashes during logging on, it's unfortunately a early stage tell tale that the processor is unstable, even if it seemed to have been 100% OK before.
If overclocking, you *MUST* try to increase the processor
voltage (Vcore) by a step to see if this goes away and if it doesn't
you *MUST* lower the processor frequency by at least 50 mhz.
If you are not overclocking, still try to increase the processor voltage (Vcore).
But if recently on the internet, there is a high chance you got a
virus and AV automatic detection did not detect it.