Vatsal_s

I originally built my system in 2016 with an i5 6600k, Asus Z170-A board and Asus ROG Strix GTX 1080. Decided to upgrade the CPU and GPU recently (see specs below) to get better performance but I've been having many issues since the rebuild. CPU, motherboard and GPU were upgraded, no other components changed and Windows was not reinstalled. Issue 1: PC fails to boot at times with error 0xc000000e, saying that a required device isn't connected or can't be accessed. If I go into bios and exit without making any changes then it boots just fine afterwards. At time the display just doesn't turn on after I press the power button. I have to power off and on again to get the system to boot Issue 2: CPU running a lot hotter (up to 45c idle) and fans running at much higher speeds even without overclocking Issue 3: Any overclocking causes lots of instability. I followed this to try to OC to 5.0ghz and set voltage at 1.3. System worked at times but would crash at other times, upped the voltage up to 1.325 but the system still crashes under load at times. I'm not sure if I got a terribly binned CPU, if the cooling isn't enough or if I'm just an idiot doing something wrong Issue 4: SSD and HDD used to show up as boot drives in the Z170-A BIOS but don't show up in the Z390-A. They are still detected as storage devices but not showing up in boot order. To improve temps I've cleaned out the cooler's radiator and fans, and reapplied thermal compound but that made no difference. Reconnected all the wiring on the motherboard to make sure everything is connected properly but no impact on boot issues. I'm not sure if its me, Windows or the components that's causing the issues. Any and all help is appreciated! Specs: CPU- i7 9700k Motherboard- Asus Prime Z390-A CPU Cooler- Corsair H100i V2 (Arctic Silver 5 thermal compound)t GPU- Asus ROG Strix 2080 Super RAM- 2x8gb Corsair Dominator Platinum DDR4 3200mhz Case- Phanteks Enthoo Evolv ATX Tempered Glass PSU- EVGA Supernova 750w G2 Storage- Samsung 960 Evo 250GB, Seagate Barracuda 1TB Lighting- NZXT Hue+ Monitors- Dell S2417DG 144hz 1440p, Asus PB277Q 75hz 1440p OS- Windows 10 Education x64