Downgrading from 21H1
Step 1: Open up settings and type: "Windows Update Settings"
Step 2: Press "View update history"
Step 3: Press "Uninstall Updates"
Step 4: Find the 21H1 feature update, right click, uninstall, and then restart your PC
*If you are on an older version of windows looking to further downgrade, I recommend looking it up on youtube as it may be a little more complicated*