Number Lock on a keyboard is usually enabled by pressing the Num Lock key on desktops, or Fn + Num Lock on laptops, with the On-Screen Keyboard serving as a backup when the physical key is missing.
One wrong tap can turn the right side of your keyboard from a number pad into arrow keys. The fix is usually a single keystroke, but the exact key varies by keyboard type. A desktop has a dedicated Num Lock key; a laptop often hides it behind an Fn-layer key. And when neither works, Windows has a hidden menu that lets you flip the switch without the key at all. Below are the three routes, from the most common to the fallback that saves a broken keyboard.
How To Enable Number Lock On A Desktop Keyboard
Desktop keyboards with a dedicated number pad always have a Num Lock key — it sits near the top-left of the keypad itself, often labeled Num Lock or NumLk. Pressing it once turns the numeric keypad on; pressing it again turns it off.
A small LED on the key itself glows when Num Lock is active. If the LED is off, the keypad acts as navigation keys (arrows, Home, End) instead of numbers.
On A Laptop Or Notebook: The Fn Key Changes Everything
Most laptops lack a dedicated Num Lock key. Instead, the function is embedded on another key, usually one of the top-row function keys (F11 or F12 on many models). The key is marked with a small padlock icon or the abbreviation NumLk in a contrasting color.
To enable it, hold the Fn key and press that function key. Sony’s official support confirms: “While holding down the FN key, press either the NUM LOCK or SCROLL LOCK to enable the function.”Sony’s Num Lock guide Press the same combination again to disable it.
Not all laptops place Num Lock on the same key. Lenovo notes that the location and symbol can vary by model.Lenovo’s NumLock glossary If the first function key you try doesn’t work, look for the padlock icon on other F-keys.
What To Do When The Key Is Missing Or Broken
When a laptop has no Num Lock key at all — or the physical key has stopped working — Windows includes a system-level backup tool. The On-Screen Keyboard includes a Num Lock toggle that behaves identically to a physical key press.
Open it by pressing Windows key + R, typing osk, and hitting Enter. On the virtual keyboard that appears, look for the Num Lock button near the top-right. Click it once to enable Number Lock on the physical keypad.
How To Keep Num Lock On After Restart (And Why It Often Turns Off)
Many users enable Num Lock, reboot their PC, and find the keypad acting as arrow keys again. That happens because the Num Lock state at startup is controlled by a Windows registry setting, not by the key press you just made.
To change the boot behavior permanently, you can edit the registry. Microsoft warns that registry edits “can cause serious problems” if done incorrectly, so back up the registry first.Microsoft Q&A on persistent Num Lock
If you choose to proceed, open regedit, navigate to HKEY_USERS\.Default\Control Panel\Keyboard, and find the value InitialKeyboardIndicators. Change this value from 0 to 2 to enable Num Lock at every boot. To revert to manual behavior, change it back from 2 to 0.
Common Mistakes That Fool People
- Assuming every laptop has a Num Lock key. Many modern ultrabooks removed it entirely — use the On-Screen Keyboard method instead.
- Confusing Num Lock with Scroll Lock. They are separate functions, though Sony groups their instructions together. Pressing Scroll Lock will not enable your number pad.
- Expecting the setting to persist after a restart. The keyboard toggle alone does not control what happens at boot — only the registry change (or a BIOS setting on some desktops) can force that.
- Missing the Fn lock. Some laptops have a separate Fn Lock toggle. If Fn + F11 seems to do nothing, check whether Fn Lock is active — it may invert the Fn behavior.
Quick Reference: Key Combinations By Keyboard Type
The table below summarizes which method matches which hardware. The third column shows the first thing to check if a method fails.
| Keyboard Type | Method To Enable Num Lock | If It Doesn’t Work, Check |
|---|---|---|
| Desktop (full-size keypad) | Press Num Lock key directly | LED on the key should glow |
| Desktop (compact keypad) | Press Num Lock or NumLk where labeled | Key placement varies by brand |
| Laptop (Fn-layer key) | Hold Fn + press the marked function key | Look for the padlock icon on F-keys |
| Laptop (dedicated Num Lock key) | Press Num Lock directly | Usually above the number pad, if present |
| Laptop (no Num Lock key at all) | Use On-Screen Keyboard: press Windows key + R, type osk | Click the on-screen Num Lock button |
| Laptop (broken Num Lock key) | Use On-Screen Keyboard as backup | Confirm the virtual key highlights when clicked |
| Any keyboard (persistent after reboot) | Edit registry InitialKeyboardIndicators from 0 to 2 | Back up registry before editing |
When The Keypad Still Acts Like Arrows
If you toggled Num Lock and the keypad is still producing arrow keys or Home/End movements, Num Lock is actually off — even if you think you pressed it. The most common cause is pressing Scroll Lock by mistake (they are near each other on some keyboards) or hitting the wrong Fn-key combination on a laptop.
Check the Num Lock LED on a desktop keyboard. On a laptop, look for an on-screen indicator: some Windows PCs show a small padlock icon in the system tray when Num Lock is active. If there is no indicator, open the On-Screen Keyboard and observe its Num Lock button — it highlights when the function is enabled.
Checklist: Verify Num Lock Is Actually On
Use this short list to confirm Num Lock is active before assuming a deeper problem.
- LED check: Is the Num Lock key’s light glowing? (Desktop keyboards only)
- Type a number: Does the keypad produce digits (4, 5, 6) or arrows (left, up, right)?
- On-Screen Keyboard test: Open osk — does the on-screen Num Lock button appear highlighted?
- Fn-layer test: On a laptop, press Fn + the marked key and try typing a number again.
- Boot behavior: Does the keypad work at the Windows login screen, or only after you type a password?
References & Sources
- Microsoft Q&A. “Turn Num Lock Permanently On.” Documents the registry change for persistent Num Lock behavior at boot.
- Sony Support. “Using the NUM LOCK and SCROLL LOCK functions.” Official steps for enabling Num Lock on desktops and notebooks.
- Lenovo. “NumLock Glossary Entry.” Explains NumLock behavior and model-specific key placement.