Thank you everyone for suggestions.
Re-installing Windows would be a bit too much for me. The problem is far from being a show-stopper.
I've done everything else, and had only one unprompted reboot in a week so. That is, the problem is still there, but it's hard to say if it may be less...
I should've probably mentioned that, when the PC reboots without prompt, TP-LINK Wi-Fi adapter stops working. I solve it by disabling-enabling it in Device Manager. Would that indicate a problem with its driver? I tried updating it, but am told that the best driver is already installed.
Yes...
Windows 10, specs below. Occasionally reboots a few seconds after coming out of sleep mode. Microsoft support were unable to help. Could it be a hardware/driver issue?
Case
FRACTAL MESHIFY S2 TEMPERED GLASS
Processor (CPU)
AMD Ryzen 7 3800X Eight Core CPU (3.9GHz-4.5GHz/36MB CACHE/AM4)...
I'm not much of a gamer, but I'd like to have the option :-) so it's a bonus if I could play, say, Mount & Blade II on high settings. Otherwise, it's the usual internet/films + data analysis (so a decent amount of RAM is important).
I've got an Acer Nitro VGC240 24" but I'm not married to it...