Question I messed up my Nvidia display settings and now my monitor keeps flashings a bunch of colours

[Jellywhatwhat]

Earlier today I tried to change the settings for my monitor. I don't remember exactly what I changed but I ticked one of the top squares in the settings and pressed apply. I had wanted to use freesync. After I did that my monitor started to flash colours like red, white, blue, green, etc and that went on and on. I want to exit this colour flashing on my screen so I can use my PC. I've tried restarting my computer many times but to no avail. Does anyone know how to undo what I did?

 

[Sagittariusss]

Initiate your computer using security mode. See which key you have to press on your keyboard when it is initialiazing.

If none of this help, you may have to take off your graphic card and plug your monitor directly into your motherboard, then from there you can undo the mess you've done.