Dell Latitude 7420 cellular network problem

You also need a WWAN card and antennas -- did you install the card (and check to make sure the antenna leads are there)?

If the antennas are missing, you either need to replace the display assembly with one having them, or you need to use an external USB WWAN adapter.

You can try these methods to fix this-

1. Check Compatibility:

Not all laptops have built-in cellular connectivity. Make sure your laptop model actually supports a cellular connection. You can check the user manual, manufacturer's website, or a retailer listing for your laptop model specifications.
2. Verify SIM Card:

Ensure the SIM card is inserted correctly. Consult the laptop's manual for the SIM card slot location and proper insertion method. Also, make sure the SIM card is activated and has a data plan with your cellular provider.
3. Enable Cellular Network Settings:

Cellular options might be disabled in your laptop settings. Here's a general process (it might vary slightly depending on your operating system):

Open your laptop's Settings app.
Look for a section related to "Network & Internet" or "Wi-Fi & Networks."
Search for options mentioning "Cellular," "Mobile Data," or "SIM card settings."
If cellular is disabled, find the toggle to enable it.

I hear you guys. I am using Dell Latitude 11th Gen Intel Core i7-1185G7 3.00GHz, 1.80 GHz internal Ram 16GB, on Windows 11 Pro. So I thought or think as soon as the laptop comes with a sim card slot then everything is there just need drivers and sim card.

The SIM card slot is there whether or not the system is configured with a WWAN card and antenna from the factory.  If it's not ordered with one, the WWAN card is absent -- and in most cases, the antenna wiring is as well unless the system is sold as 4G/5G ready.

@ejn63​  meaning i still nned to buy which one is much cheaper between the USB and Internal WWAN card?