Frequent System Freezing followed by Crash (No BSOD)

For a while, my system has been freezing and then crashing. Initially I thought this may have been a problem with the graphics driver as the driver would frequently crash, but I have solved that issue and am still experiencing crashes. When I opened device manager recently, there was an error symbol on my blu-ray drive. I believe I have solved that issue as well though. I have run MemTest which found no issues with my memory. I believe the issue may be with my CPU. It is running at about 75 Celsius (According to ASUS AI Suite II), 55 Celsius (according to the BIOS) during unintensive operations such as internet browsing. This is the only thing I can think of that may be causing the issue, but the fan seems to be running just fine. My motherboard also has two assist fans which are running and my case has 7 fans and runs cool. I'm not sure what to do now or if the CPU even really is the issue.

run the test on prime95 , both max heat consumption and the other test max cpu. You'll KNOW with prime95 if it's your hardware. Do you have a laptop? 75c during light load sounds pretty hot if you're on a desktop.

Prime95

It is a desktop. I ran the Small FFTs (maximum heat, etc...) test. I've attached the results here, it didn't encounter any errors. Not sure what the other one you want me to run is. I've also attached a picture of the test dialog window that opens so you can let me know which one to run.

You can run small fft test and in place large fft... maybe each for 10 or 20 minutes. If your system doesn't freeze or crash during these test, I believe you should be able to rule out CPU or Memory problems.

Ran that one two. Neither gave any errors. Maybe it's not the CPU, but it is still strange that the CPU is so hot. I forgot to mention this before, but when it restarts after a crash, it doesn't boot windows immediately. Instead it displays a screen that says "CPU over temperature!" I don't rhink that really changes much though. Is there a program that can give a fairly accurate value for the CPU temp? Also, another thing that may be the cause is Firefox. The crashes seem to happen when I'm using the browser. It's hard to say if this is really the cause though as I almost always have it open. I do often have a lot of tabs open, but many are often left unloaded and my hardware should be able to handle it I think.

if you get temp messages and you're running that hot, you should maybe re-thermal paste your cpu and consider a better heatsink/fan combo. There's probably something set in the BIOS where the computer will shutdown if it exceeds 90c or 100c or some other temp.

Yeah, maybe I'll try reapplying the thermal paste, granted I can find it.

Out of the frying pan and into the fire it seems. The old thermal paste which I had applied originally in 2012 was not looking good. I removed it using rubbing alcohol wipes while wearing an electrostatic shock bracelet. I removed the CPU from the MOBO to remove the thermal paste from small crevices. None got on the MOBO. I then reapplied the paste and reattached the fan/sink. The fan/sink will not sit properly on the CPU, it never has. There is a bit of wiggle room. I closed the computer up and restarted it. Upon restarting it said that a new CPU was installed. I then booted into windows and it crashed before I could sign in. Second boot, I made it a little further. Likewise with the third. The system seems to be running very slowly though. I guess removing the CPU was not a good idea. I ensured that it was seated properly though, and there didn't appear to be any bent pins on the MOBO. Not sure what I should do now. I will let it cool down for a while and then try to boot again.

if the heat sink doesn't sit firmly on the CPU, there's no way the cpu can transfer heat to the heatsink! I don't know how it would 'know' a new CPU was installed but I can see something being put there to trigger this depending on MOBO. I would also reset the BIOS settings at this point, may not do much but can't hurt. There's really no reason your system should be running slower just by doing a cpu reseat. I suggest you remove some RAM sticks and other hardware to see if you can narrow down all your issues you're having to other hardware installed on the mobo.

Did you get any paste on the chip itself or something?

Yeah, that's likely the heat issue. I can try to tape it or something, but there's no way to get it to sit tightly. I'll try resetting the bios. As far as the system running slower, it doesn't make any sense to me either. I will remove ram to eliminate that possibility for sure, but I doubt it's the cause as it passed memtest86. I'll also try removing the GPU, other than that, there isn't much else I can really remove. When I was removing the old paste, there was some on the chip, but it was on the top part and on plastic, not on any connections. I'm pretty sure it doesn't conduct electricity though. It was at the bottom of the chip, on the black part in the picture I've attached. I just booted again. It was better than before, but still sluggish. CPU usage was at ~50% as opposed to the 100% it was at before. It crashed again shortly after opening firefox