First, Create a restore point its important,if you make a mistake in the customization, the restore point help to restore the system to its original state
The custom themes theme will only work if you install the theme patcher, so you must install the Ultra UXTheme Patcher to use the third-party theme on your Windows.
Removing the ribbon menu (toolbar) from Explorer : Windows 10 and 11
Windows 10 users must use the OldNewExplorer program to remove the ribbon menu. Extract the downloaded OldNewExplorer file and then open the oldNewExplorer.exe application. Select the “Use Command Bar” box and uncheck the last two boxes then click Install to install OldNewExplorer.
Windows 11 users can hide the ribbon menu using StartAllBack. Install the downloaded StartAllBack application, then open the Explorer option and select the Win7 command bar.