Hi
Start in control panel device manager for network devices
To see if a device without a driver exists
If no device exists check if function key to enable wireless will work
Or check airplane mode is off
Read user guide to see if a physical switch exists
Final place to check is in bios or uefi for enable disable wireless
If this does not work contact Dell technical support who should be able to talk you thru the procedure
Let us know the results
Regards
Mike Barnes