TO DISABLE ALL ADS ON WINDOWS 11

Open Settings by pressing Win + I.
On the left side menu of the Settings page, select System.
Under System, click Notifications.
Scroll down to the bottom and toggle off "Offer suggestions", "Get  tips and suggestions", and any other suggestion/tip.

Now click on Additional settings under Notifications.
Uncheck "Show the Windows welcome experience"
Uncheck "Suggest ways"
uncheck "Get tips and suggestions"

Open Settings.
Click on Privacy & security.
Click the General page on the right side.
Uncheck "Show me suggested content" 
Uncheck "Let apps show my personalized ads"

Open Settings.
Click Privacy & security.
Click Diagnostics & feedback page on the right side.
Click Tailored experiences 
Uncheck "Let Microsoft use your diagnostic data"

Open Settings.
Click on Personalization.
Click the Lock screen page on the right side.
Scroll to the "Personalize your lock screen" section
Uncheck "Get fun facts, tips, tricks"

Open Settings.
Click on Personalization.
Scroll to the Start page from the right side.
Uncheck "Show recently added apps" 
Uncheck "Show most used apps" 
Uncheck "Show recently opened items"

Open Settings.
Click on Personalization.
Scroll to the Taskbar page on the right side.
Uncheck Widgets

Open File Explorer
Click the See more (three-dotted) menu button 
Click on Options.
Click the View tab.
Uncheck "Show sync provider notifications"