If the only issue appears to be a slow clock then just
sync your Windows clock with an internet time server each time you boot up.
Your hardware is a few years old - an aging oscillator could be losing calibration, an old electrolytic could be leaky, the thermal goop on your processor or GPU card might have cooked off, your cooler block or pump or rad(s) could be sluggish and gummy, your elderly PSU could be delivering standby power filled with dirty ripples and surges, there might be all sorts of component-level hardware faults and inaccuracies. If your hardware was often (ab)used by the stresses of overclocking or heavy gaming or coinmining or something then it'll have less longevity. But if it all seems to still be working (almost) perfectly with a workaround and there's no other specific problems then there's little need to do a full rebuild or rush towards costly hardware upgrades/replacements.
Your best option, I think, is to comb through your BIOS and confirm that all your timings and voltages and other settings are within normal parameters. Monitor temps for a while, just to be sure all is well. And backup your valuable data on a regular schedule, lol.
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