I would yes as heat issues are more of a problem here than whatever speed reduction you get from an 8x slot I think, but with cramped quarters like that I would keep in mind an aio cooler for the cpu as a possible future upgrade.
If you did overclock cpu once upon a time, are you sure all the settings went back to default? Try going into bios and resetting to default values to see if this helps. You can also check what your clocks are with something like HWMonitor which should tell you what's going on, and will also allow you to check your voltages, to see if they're appropriately set.
If it's happening even while browsing then it might not be a load issue at all. It can happen if some files got deleted, sure, but if you ran a scan, it would be odd that it didn't detect it (though not impossible). You can run repair from the windows boot cd/usb, after all you don't lose anything by doing it and it's the best method for fixing/checking windows installation.
You can try recovery (rolling back to previous settings), but make sure the recovery point is not from some really old date (like years old) as that can in fact mess up your system and might need a repair/reinstall of windows after.
The dump file wasn't actually more informative (to me and I'm not expert on them) than your already posted info was, so just from looking at it, I would be concluding this:
https://answers.microsoft.com/en-us/windows/wiki/windows_10-update/bugcheck-code-124/98c998d2-447a-40ce-ae1f-8211e355f14d