Windows 10: How do i make my windows 11 go back to windows 7 or windows 10?

Hey guys, i have a DELL laptop and I installed windows 11 on it like a year ago and it made my laptop worse. I wanna revert my system to windows 7 system. I've tried everything but nothing worked sadly, I even tried to make my laptop revert back to windows 10 but that option is closed. is there any chance I can make my laptop go back to windows 7 or windows 10?in windows 11, whenever i want to play a game or use a browser. it made my laptop screen appear black at random times, it fades but sometimes it kind of just makes me lose all of my progress like for example if i have three tabs open at

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