HDD worked flawlessly so far, it's an old hdd from like 2014, crystal disk info and hdd sentinel both showed good health.
Then a couple days ago pc started behaving weirdly, it didn't recognize my 2nd ssd that was bought about a month ago, then after a couple reboots it recognized all drives just fine, then today I had a couple of boot sequences where a part of the os didn't even initialize or something, icons were missing, tabs in the browser were missing, crystal disk info couldn't even load, showed something like "software doesn't fit your system".
Then after another couple reboots and fiddling with sata connectors and power connectors inside the case, making sure all is plugged in well, system starts normally again, but the videogame I played just yesterday won't load (it's on that HDD). Opened crystal disk and sentinel again, both show that HDD went from 100% to 80% in one day and acquired a number of bad sectors (says 8). HDD sentinel graphs show rapid decline in one day.
How come a perfectly good drive just goes bad like that in a day?
Over the last year I opened most of the files there at least once, except for some stuff I forgot about a long time ago, but it's maybe a gig at most in total. All seemed to work fine.