Keyboard Not Working? Four Symptoms, Four Different Causes

Which of the four is yours?

Wrong characters — start here

If pressing @ gives you ", or the number row produces unexpected symbols, or a key that should be a hash sign gives a pound sign, your keyboard is perfectly healthy. The operating system is interpreting it with the wrong layout.

This happens because most systems include a keyboard shortcut to cycle input languages, and it is very easy to trigger by accident — commonly a modifier plus Space or Shift. People hit it, everything goes strange, and conclude the hardware has failed.

• Windows: look at the language indicator near the clock. Click it and pick the right layout. To stop it recurring, go to Settings → Time & language → Typing → Advanced keyboard settings → Input language hot keys, and disable the shortcut. Also remove any layout you don't actually use.
• macOS: System Settings → Keyboard → Text Input → Input Sources. Remove layouts you don't need, and check the shortcut under Keyboard Shortcuts → Input Sources.
• The clue that confirms it: the mismatch is consistent and follows a pattern — a British layout swaps @ and ", a US layout does the reverse. Random dead keys are a different problem.

The other settings that make a keyboard behave oddly

• Num Lock. On a laptop without a separate number pad, an accidental Num Lock turns part of the letter area into a number pad. Suddenly "jkl" types "123". Press Num Lock — often needs the Fn key — and it's fixed.
• Sticky Keys. Triggered by pressing Shift five times, which happens by accident in games. Modifier keys then latch on instead of needing to be held.
• Filter Keys. Triggered by holding right Shift for eight seconds. It deliberately ignores brief keypresses — so the keyboard appears to miss letters, which feels exactly like failing hardware. This one causes a lot of unnecessary replacements. Both are in Windows accessibility settings.
• Mouse Keys makes the number pad move the cursor rather than type numbers.

Nothing at all

No response anywhere, including at the login screen.

Wired or built-in

• Try a different USB port, directly on the machine rather than through a hub, monitor, or dock.
• Check the lights. Press Caps Lock. If the indicator changes, the keyboard is alive and being seen — this is a software problem, not hardware.
• Restart properly. On Windows, do a full shutdown rather than a restart. Fast Startup can carry a broken driver state across a normal reboot, which is why the problem seems to survive restarting.
• Reinstall the driver. Device Manager → Keyboards → right-click → Uninstall device, then restart. Windows reinstalls it cleanly. Use the on-screen keyboard to navigate if you need to.
• On a laptop, drain residual power: shut down, unplug, remove the battery if it's removable, hold the power button for 30 seconds, then reconnect. This clears a surprising number of dead built-in keyboards.
• Check the ribbon cable if the keyboard died after the laptop was dropped or opened. This is a repair-shop job on most models.

Some keys work, others don't

Selective failure is almost always physical.

• Turn it upside down and shake it. Genuinely. Crumbs, hair and dust collect under keycaps and stop the contact closing. Do this over a bin, firmly, and be surprised at what comes out.
• Compressed air at an angle, working across the board rather than straight down, which just relocates debris deeper.
• Remove the keycap if you're comfortable. On most mechanical and many membrane keyboards, keycaps pull straight up. Clean underneath, check the switch, refit. Laptop keys use delicate clips — look up your specific model before prying, because they break easily.
• A cluster of adjacent dead keys suggests a damaged trace in the membrane rather than debris — often the aftermath of a spill months earlier. That usually means replacing the keyboard.
• If a key repeats or sticks, that's usually contamination — something sticky under the keycap.

Typing lags behind

Letters appear a second after you type them, or characters go missing in fast typing.

• Check whether it's only in one application. If typing is fine everywhere except one program, that program is the problem — a browser tab running something heavy is a classic cause, and our browser guide covers finding it.
• Check whether the machine is simply overloaded. If everything is sluggish, the keyboard is a symptom. See our slow computer guide.
• Filter Keys again. It is specifically designed to ignore quick keystrokes, so it looks exactly like dropped input.
• On wireless, interference. See the next section.
• Check the repeat delay settings if keys repeat when you didn't hold them — Windows Control Panel → Keyboard, or macOS Settings → Keyboard.

Wireless keyboards

• Batteries first, always. A dying battery produces intermittent and lagging behaviour long before it produces nothing — which is much more confusing than a clean failure. Swap them before investigating anything else.
• Move the receiver. A USB dongle plugged into the back of a desktop, behind a metal case, has a much worse connection than one on a front port or a short extension cable. This single change fixes a lot of "unreliable wireless keyboard" complaints.
• USB 3 devices interfere with 2.4 GHz wireless. A well-documented effect: an external drive or hub next to the receiver can flood the band. Move one of them apart.
• On Bluetooth, re-pair from both ends — remove the keyboard on the computer and reset the pairing on the keyboard. Our Bluetooth guide covers why half-deleted pairings cause this.
• Bluetooth keyboards can't be used to log in on some systems before the desktop loads. Keep a cheap wired keyboard in a drawer for exactly this.

If you spilled something

What you do in the first minute matters more than anything afterwards.

1. Power off immediately — hold the power button. Don't shut down politely; the point is to stop current flowing.
2. Unplug it, and remove the battery if you can.
3. Turn it upside down in a tent shape so the liquid drains out rather than deeper in.
4. Leave it for at least 48 hours in a dry, airy place. Don't use a hairdryer on hot, and don't use rice — it does nothing and leaves starch behind.
5. Don't test it every few hours. Powering on a wet board is what turns a recoverable spill into a dead machine.

Water often dries out with no lasting harm. Anything sugary — coffee with sugar, juice, fizzy drinks — leaves a residue that keeps conducting and corroding after it dries, so a professional clean is worth it even if the machine seems fine.

The test that separates hardware from software

If you're still unsure, these settle it:

• The on-screen keyboard. Open it (Windows: Ease of Access; macOS: Accessibility Keyboard) and type. If the on-screen version works correctly and the physical one doesn't, it's hardware. If both misbehave the same way, it's a setting or the application — and this is the fastest way to confirm a layout problem.
• Type at the login screen or in the BIOS. Neither loads your operating system's drivers or settings. A keyboard that works in the BIOS but not in Windows is a software problem, full stop.
• Plug it into a different computer. The cleanest test of all for an external keyboard. If your mouse went at the same time, that usually means one shared cause — see our mouse guide.
• Plug a different keyboard into this computer. The other half of the same test — and for a laptop, it also tells you whether it's worth repairing the built-in one or just using an external.