@ChipFrazier1950 

I understand that after restoring your laptop to factory settings, you are being prompted to enter a network security key, but the field only accepts numeric characters, while your WiFi password contains both letters and numbers.

The network security key is simply another term for your WiFi password. Normally, this password can include both letters and numbers. If your device is only allowing you to enter numeric characters, it could be due to a limitation in the input method or a prompt for a PIN instead of the usual WiFi password.

Here’s what you can try:
1. Check the prompt carefully: Some devices ask for a PIN (which is usually an 8-digit number found on the bottom label of your TP-Link Deco Mesh device) instead of the WiFi password. Try entering this default PIN if available.
2. Switch input modes: On some devices, you may need to switch the input mode to allow letters. Look for an option to change from 'PIN' to 'Password' or 'Security Key'.
3. Use the default password: If you have reset your router or Deco Mesh device, the default WiFi password (often found on the device label) should work.
4. If you’ve changed your WiFi password: Make sure you are entering the correct, current password. If you can’t remember it, you may need to reset your router again and use the default password.

If these steps do not resolve the issue, please let us know more details about the exact prompt or any error messages you see, so we can assist you further.