are you indian? anyway if it's not the ssd then it could be ram. run mem test for a couple of hours.
South american (argentina) power utility here is probably far worse than india.
Not ram, i swapped by identical sticks from another machine, run Memtest86 for an entire day, perfect both.
also i have a better way to test memory (sometimes Memtest86+ miss some memory hiccups) using quickpar2
probably the most memory intensive app i know, i create the par2 files for a 4GB iso image for example and
then check the par2 against the file, and if it fails, memory is the problem 99% of the time.
the problem is that quickpar is quite old, and doesn't like windows7 or newer, and also doesn't like more than
3gb of ram, so i have to virtualize it in order to be able to run it, but still the most reliable memory tester i found so far.
my bet is that the primary cause of the issue is what achow101 said in his first post, i think he nailed it. that
defender is from time to time messing with the blocks on disk and fucking things up, i disabled defender, we'll see
but my bet is that defender was the problem.