Because the external keyboard works correctly, the issue is almost certainly with the built‑in laptop keyboard (hardware, stuck key, NumLock, or debris), not Windows itself.
Try these steps:
- Check for NumLock or Fn/NumLock
- On many laptops, when NumLock is on, part of the main keyboard acts like a numeric keypad (for example, U/I/O/H/J/K/M typing numbers or extra characters).
- Turn NumLock off (often
Fn + NumLock, or a dedicatedNumLockkey). If using an external keyboard, make sure NumLock is off there too, as one case was caused by NumLock being enabled on an external keyboard and affecting the built‑in keyboard.
- Test for debris or stuck keys
- Debris under keys can cause intermittent or wrong characters.
- Use compressed air to blow under the affected keys.
- Wipe the keys with a slightly damp microfiber cloth.
- Compare behavior with an external keyboard
- Since the external keyboard works fine, this strongly suggests a hardware problem with the laptop keyboard.
- If the external keyboard starts showing the same issue, then it may be a software/driver problem instead.
- Check in Safe Mode (if possible)
- If the built‑in keyboard works correctly in Safe Mode, a third‑party app may be interfering.
- If it still types wrong characters in Safe Mode, that again points to hardware.
- If the problem persists
- The built‑in keyboard is likely failing and may need repair or replacement by a technician.
- Continuing to use the external keyboard is a valid workaround until the hardware is serviced.
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