What I see in Reliability History is multiple and varying errors. That, again from my view, is a sign of a faltering and failing PSU.
The problems began on the 14th and then became worse on the 21st with a few interim errors in between. Check the details of those dates to see what was logged. ( Event Viewer can be used as well. Just requires more time and effort to navigate and understand. You can change and filter views to help narrow down problems.)
Overall the PSU may now simply be unable to keep up with power demands. Remember that PSU's provide 3 different voltages (3.3, 5, and 12) to various system components. Any interruptions in a given voltage or just an out of tolerance voltage can and does wreak havoc on the supported host system.
Unexpected shutdowns (Loss of power) corrupt files: "dism", "sfc /scannow" fix the problems and files get corrupted again.
= = = =
That said, there are some things that can be done.
First, if at possible, ensure that all important data is backed up and proven to be recoverale and readable. Backup locations should be away from the problem PC in question,.
Power down, unplug, open the case.
Clean out dust and debris.
Verify by sight and feel that all connectors, cards, RAM, jumpers, and case connections are fully and firmly in place.
Use a bright flashlight to inspect for signs of damage: bare conductor showing, melted insulation, pinched or kinked wires, corrossion, missing or loose screws, blackened or browned areas, moisture, dead bugs, cracks, swollen components.
Hopefully the problem is a loose connection somewhere. Heating and cooling cause expansion and contraction that will and does cause connections to wiggle loose. As do vibrations.....
Check every thing carefully and continue to watch the logs. Patterns may be noted. Or some error may be or become more predominate.
Take a couple more screenshots of Reliability History - especially on dates where there are lots of errors. Check the technical details. They may proven helpful as well.