At one time - the mains supply out here was a bit flaky, so I installed a 2nd-hand APC 1500 Smart-UPS. Since then, it's had two new sets of batteries, and has (generally) behaved itself - allowing long enough to shut down the Windows10 PC (left on 24/7) gracefully in the event of power cuts (assuming that you happen to be near the PC when the outage occurs).
The last few weeks, I've noticed that the PC seems to have rebooted itself while I've been away from it. Just now I watched as the UPS gave a 'clunk', dropped the power completely and then, after a few seconds, restarted itself - all the while indicating that the house mains was stable & present..
These power outages don't seem to upset Win10 at all - so I'm wondering if it's worth throwing another set of batteries at the UPS (the last set were installed Jan 2016 and cost 112 euro) - or just unplug the UPS and feed the PC with raw mains, and live with any consequences...
Back in the day, pulling the power on a Windows box without shutting it down properly used to be a recipe for disaster - though perhaps modern disks are more tolerant of this sort of abuse..?
Worth throwing another set of batteries at the thing - do you think? Comments / suggestions, please? Thanks, Adrian