Question Frequence unsupported

[CocaDonut]

Hello everyone, I'm new to the forum, and here is my problem.
So, a couple days ago i was messing around with my displays. I have two screens connected to my computer. The first one is a 144hz gaming screen and the second one is an old full hd basic monitor. So i was messing around with resolution settings on my second screen and by mistake i set it to 1920 x 1200. My screen suddenly turned black and now shows the message "frequence unsupported". For some reason, im unable to switch it back to it's normal resolution (1920x1080). My primary screen still works but i can't acess the settings to my second screen. Ive tried having only one screen connected but it just shows a black screen. I know the screen is still working because sometimes at launch, it displays the bios gigabyte page. Ive tried connecting it to my gpu instead of mobo and still nothing. I also tried running the safe mode but for some weird reason it would only change the resolution on my primary screen, not the one that went black. Does anyone have an idea of what the issue could be and how to fix it? Thanks in advance for your help

 

[rgd1101]

power down. unplug the primary screen, boot into safe mode

 

[CocaDonut]

power down. unplug the primary screen, boot into safe mode

I've tried that, but for some weird reason i can't boot into safe mode from my BIOS... Ive tried f8, ive tried loading into the bios and finding safe mode but it isnt there. Only way i can get into safe mode is through windows, but i need a functionning screen to do that. And if i launch safe mode from my primary screen it weirdly doesnt cary onto my second screen.

 

[CocaDonut]

Well... Finding a legit solution to this issue was really frustrating me... so i kinda cheated and downloaded a program to bind certain keys to change my screen resolution. And it worked! So if any of you have that same issue, try HotKey Resolution changer. Thanks @rgd1101 for taking the time to answer!