Blender Shortcuts Not Working
Keys do nothing or do something unexpected
Also known as: Blender hotkeys not working · Blender keyboard shortcuts not working · Blender numpad not working · Emulate numpad Blender · Blender keymap
Quick answer
Blender shortcuts act on the area under the mouse cursor, so the most common reason a key does nothing is that the cursor is over the wrong editor. Hover over the 3D viewport before pressing a key. Next check the mode, since many shortcuts differ between Object Mode and Edit Mode, and make sure no text field is active.
How to fix it
On a laptop without a numpad, enable Emulate Numpad in Edit > Preferences > Input so the number row switches views. Check that the Keymap preset in Preferences is Blender and not Industry Compatible, which changes many keys. If a single shortcut still fails, search for it in Preferences > Keymap, because another addon or a custom keymap may have taken it, and restore the default keymap if needed.