It looks like you have the February 2026 Windows 11 update (KB5074109), which introduces a Single Page Start Menu layout. Microsoft has merged your pinned apps and your full app list into one long, scrollable window.
In this new design, the "All apps" section is now permanently visible on the main page rather than being tucked behind a button. By default, it often opens in "Category View", which groups your apps into square boxes like "Productivity" or "Games".
There is currently no simple "Off" switch in the standard Settings menu to remove the bottom half of this new layout.
If you don't like the boxes, you can at least make them look like a standard list again:
Open the Start Menu.
Click the View dropdown menu in the top-right corner of the bottom section.
Select List to return to a classic alphabetical list, or Grid for a denser icon layout.
If you want to completely hide that bottom half and go back to having only your pinned apps visible, you have to use a Registry edit.
Warning: Modifying the Registry can cause system issues if done incorrectly. Always back it up first.
Open Command Prompt as Administrator.
Copy and paste this command, then press Enter:
Reg add "HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer" /v NoStartMenuMorePrograms /t REG_DWORD /d 1 /f
Restart your computer for the change to take effect.