Hello guys. I've had many PC problems these days, but first a little backstory: ever since upgrading my graphics card in October 2015, my old hdd started making a weird clicking noise once a month. However, this clicking (and freezing) got extremely frequent in June, and after diagnosing the hdd with several corrupt sectors, I decided it's time to get a new one. And that was a factory new WD10EZEX with 7200rpm and 1tb of memory, using a SATA3 port. My motherboard has a SATA2, but other than slowing the hdd down that shouldn't present a problem. After setting the partitions right I installed windows 10, which I was using since day 1 without a problem. After that and setting up some important programs, I redownloaded DS3 to see if it will freeze again. It didn't freeze (right away) but I did notice an odd buzzing sound from the PSU whenever playing demanding games like DS3, Doom etc. Also, the buzzing would stop every 10-20 seconds, when the game would freeze. The next day however, while I was away and the pc was on, I came back to see it crashed. Turned it on, and the regular 8 sec startup was turned into a 40 sec one, because after 8 seconds on the win 10 logo screen thingy, the monitor turned off and on again, alongside the mouse and keyboard LED and continued the loading animation, but at 15-ish fps and lower resolution. The next 5min after launch the hdd was at 100% usage due to some system process. I downloaded HD Tune pro again to see if this one too is corrupted, but it found nothing. I kept playing ds3 and it suddenly froze and crashed again. This time, after launch I had no internet access and it kept freezing whenever I clicked anything. After running Windows memory scan which found nothing, and hardware troubleshoot which only found a missing coprocessor driver (which I can't download) I decided to revert to win 8.1. And that's when it culminated, by getting a DPC_WATCHDOG_VIOLATION BSOD and, after restart, not recognizing the hdd until I replugged it. I'm sorry if this post was too long, but any help would really be appreciated!