I recently switched from an i3-8100 to an i7-9700k and I installed everything correctly with thermal paste application and I reinput the CPU cooler perfectly. I booted up my PC which first time boot showed a blue screen saying there was a problem with startup. I clicked continue to Windows and everything was fine at the start. I checked my PC Specs and Windows had correctly Identified my i7-9700k. Until, the fan speeds kept going up and down, fast and slow, in very inconsistent patterns. If I opened a program the fan speed would shoot up for a few seconds, and every now and then it would go super fast for a while. I monitored my CPU's temp using MSI Afterburner, and with nothing else open it was sitting around 60-65, and on some cases it would just shoot up to 70. I decided to try a VR game as the i7 is reccommended for VR, but the second I launched the game, my headset crashed, the PC froze and wouldn't respond to anything. I had to hold the power button to power it off. I rebooted and launched rocket league which worked fine, but something just felt off. From then my PC would keep going loud on the fans and crashing on some games, so I just switched back to my i3 for now (which works fine). I have requested a return on the i7 thinking it could be something to do with my PSU not being powerful enough, but I'm not sure. I have 14 days to return it but if someone could diagnose and give me a fix to my issue that'd be great. Thanks.