Windows 10: PC freezing/crashing AFTER windows reset w/ files

Recently and out of nowhere, my PC has started freezing/crashing during regular use. My first instinct was a thermal issue, and I noticed the CPU was idling a little over 50C, so I took the AIO off, removed and replaced the thermal paste which was quite scarce, and tried again. Didn't work, so when I could get past freezing/crashing into Windows Recovery, I reset Windows and selected to keep all my personal files. The Windows reset happened normally, but the PC froze on initial Windows boot, and had to be reset. The PC still has the same symptoms as before, and since then I've found some very

:)

 

all games crash!

ive watch my temps and both the cpu and gpu are within normal ranges. when it freezes it simply freezes the image and stops the sound. i must reboot to get back to windows.

 

all games crash!

I suggest you run rthdribl > http://www.daionet.gr.jp/~masa/archives/rthdribl_1_2.zip
Increase the window size step by step and watch your vga temps permanently.
What happens?
If it crashes, run at stock speeds as suggested before and retry.

P.S.: When your system locks, does the display signal turn off after a time?
Stuttering sound or no sound at all when freezing?
What X1800XT model do you own exactly?

 

PC Freeze on Heavy use/streaming w/ Gaming

Thanks zbook - see below screenshots. All looks well, to my untrained eye?

Drive 1: data drive - HDD










Drive 2: SSD