Computer problems while gaming

[fireangel1996]

Hello, i have been currently having problems with my pc! i have a Intel Core i7 4790K cpu, the problem with it is that it is always running at 70c even when not under full load, even while it is idle, im going to be buying a new Fan and replace the thermal paste on it next paycheck and see if that fixes it, BUT my main problem has been in games.

Specs.
Intel Core i7 4790K
8.00GB Single-Channel DDR3
MSI Z97 GAMING 3 motherbord
4095MB NVIDIA GeForce GTX 970 and a
931GB Western Digital Hard drive { hard drive is more than 5+ years old}

My problem is that recently some games have randomely uninstalled there selfs and i have been having to reinstall games, But also while i have been playing games there has Been Massive stuttering / freezing / huge frame drops to the point that the game is unplayable, but this only happens in Ark survival , Gta 5 and the Newer Doom, every other game i have played runs at a smooth 50-60 fps and i have no idea why the other games play like dog shit while others have been fine. i have noticed when i play some games though that parts of the map dont load and there is just void untill it loads in , this has happend some in gta, and Black desert online does anyone have any idea why i have been having theses weird problems ??? { i have done cleaning programs to see if there was bugs but there isent, and everything besides CPU runs in norm temps for playing games, grafs card gets to 70 c Max while playing very intense games} Any ideas

 

[fireangel1996]

another thing to add is that my Hard drive is always running at 100 % while playing games idk if thats normal. and memory while playing gta is running at 85-90%

 

[fireangel1996]

and i have done all driver updates for gpu

 

[fireangel1996]

just today i have had to Uninstall Gta 5 and now im reinstalling it for no reason and i only had the game installed for a week, i tried opening it and it said that it was not installed...