You may want to move up to latest Ubuntu to see if they supply a driver for your unknown WiFi card and laptop. I no longer work hard at finding drivers for Linux. I just test a newer version until the WiFi shows up.
If you wish to go beyond the usual, then post in Ubuntu forums but leave out the email address and supply the laptop make, model along with the laptop's make, model WiFi card.
Processor: Intel® Celeron(R) CPU G1840 @ 2.80GHz × 2
Ubuntu 16.04 32-bit
D-Link router DSL-2750 U
email: (disabled by moderator edit.)
My PC is DSL connect now I want connect WiFi to a laptop on the same room.
No WiFi on System Settings > Network.
Need help to fix this.
Note: Moderator removed email address in the clear for spam control.