You press the key printed with one symbol and a different symbol appears. The keyboard may not be broken. The operating system’s active input layout can interpret the same physical key differently from the layout printed on the keycaps.
Microsoft’s keyboard and language guidance distinguishes input-layout settings from the Windows display language. Changing the keyboard layout does not necessarily change the language of menus. Similar distinctions exist on other systems, but their controls and shortcuts differ.
Test in a harmless text field
Open a plain document and type a few non-sensitive characters that are behaving unexpectedly. Check the active input indicator and compare it with the physical keyboard you are using. Do not test by typing a real password into a document or chat message.
If several layouts are installed, select the intended one deliberately. Then test the affected keys again. A shortcut may have switched layouts accidentally, or an external keyboard may use a different physical arrangement from the laptop’s built-in keyboard.
Keep the distinction between layout and hardware faults clear. A consistently remapped symbol suggests a different question from an intermittently unresponsive key. If only one application behaves differently, check its input or shortcut settings before changing the entire system.
At a sign-in screen, inspect the input-language control if available. The layout there can matter even before your usual desktop settings are visible. Follow the operating system’s official instructions rather than repeatedly entering a secret while assuming every key produces its printed character.
Once you have identified the correct setup, remove unused layouts only if you are sure they are unnecessary for you and other authorised users. Keep a note of the setting name rather than a secret typed with it. The practical goal is a predictable relationship between your hands, the keycaps and the text on screen.