You should get a qualified professional to check your house's electrical wiring so this don't happen again in the future.

Thank you for reply. Also last question. I tried to reproduce this by turning off and on power cord and booting up pc, but not happened again. Windows booted with 144hz and not go itself to other value. So i guess it was maybe random? And what now, dont worry or just ignore?

If it's a one time thing, I would just ignore it. 🙂

Really sorry for my language. If i can i explain this more clearly.

Few days ago I get power outage.

Pc was running in fire strike benchmark with monitor ON.
At the same time my mother was powering on electric oven in kitchen.
And then power went out in house.

Just before power went out, pc was running in Fire Strike test, and monitor was on.
When power went out,pc goes off and monitor goes off.

When power back ,monitor turns on itself . Then I booted pc , all was looking fine, Windows 10 booted with 144hz

But after moment I shutdown pc by clicking shutdown in Windows 10 and I manually turned off monitor.
After 30 minutes ,first I turn on manually monitor,then I boot pc again. Windows 10 booted with lower refresh than 144hz.( on nvidia panel still 144hz )
To restore 144hz I just turned off monitor and turn on again. And this not happened since.

And my question. It was related to this power outage or just coincidence?

And I am not able to reproduce. Turning off pc few times and booting again,and nothing,still 144hz. Even I cut power 3 times to check,but still 144hz on boot.

So maybe that was glitch.windows,system,drivers or something but not related to that power outage? Or maybe power outage was the reason, but the problem didn´t show up immediately?
Last edited: 21 minutes ago

Too many appliances plugged into the same circuit in your home.
This could actually be a serious issue - I mean a fire hazard - if the oven can affect other things. The oven is always supposed to have its own breaker.

But sudden power loss events like this won't affect a PC much, unless they occur frequently.
Windows will complain a little at first reboot. Volatile state data (like the active refresh setting on your monitor) might be lost, but it's usually easy to restore back to preferred settings. The computer and monitor are not damaged just because they "forget" the user settings when power is reasserted.

If this worries you, especially if it happens often, then you should buy a battery UPS for your system. It doesn't even need to be huge and mighty (and expensive), only good enough to provide a few minutes power so you can gracefully shutdown the system when needed.

And you might want a qualified electrician to check your home wiring.

It happened once. After this i booted and restarted pc many times, and refresh was still 144hz at startup.

You said:"Windows will complain a little at first reboot. Volatile state data (like the active refresh setting on your monitor) might be lost, but it's usually easy to restore back to preferred settings. The computer and monitor are not damaged just because they "forget" the user settings when power is reasserted."

So first boot after unexpected shutdown ( due to power outage ) was fine. But second boot was with that lower refresh. So that was still propably related to this 1 unclean shutdown ? : )


ps:
We just not turning oven right now. And electrician coming in next week to check all.

And sorry for my language.

No need to apologize, English is not my first language either.

Windows sometimes does strange things in strange ways. It's not uncommon to need two (or more) restarts before user changes persist.

So it was related to outage,voltage,system or monitor firmware?