I have finally installed Zorin OS 18 on my computer. But now I simply can not connect my Internet. No matter what I tried, it simply says "WiFi adapter not found". I tried multiple forums and nothing helped me. I really need help on this one. It’s my first time using Linux, so this really doesn’t give me a good first impression and I know. 
Can you please open terminal (cmd) prompt with ctl+alt+t and paste into it:
sudo lshw -C network
and relay what network card you have and if it lists any driver for it.
*-network
description: Ethernet interface product: RTL8125 2.5GbE Controller vendor: Realtek Semiconductor Co., Ltd.
physical id: 0
bus info: pci@0000:0a:00.0
logical name: eno1
version: 05
serial: bc:fc:e7:52:b7:92
capacity: 16bit/s width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress msix vpd bus_master cap_list ethernet physical tp mii 10bt 1
Obt-fd
100bt 100bt-fd 1000bt-fd autonegotiation
configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=6.14.0-33-generic
firmware=rt18125b-2_0.0.2 07/13/20 latency=0 link=no multicast=yes port=twisted pair resources: irq:38 ioport:e000(size=256) memory:f6b00000-f6b0ffff memory: f6b10000-f6b13fff
*-network UNCLAIMED
description: Network controller product: MEDIATEK Corp.
vendor: MEDIATEK Corp.
physical id: 0
bus info: pci@0000:0b:00.0
version: 00
width: 64 bits
clock: 33MHz
capabilities: pciexpress msi pm cap_list configuration: latency=0
resources: iomemory: fc0-fbfmemory:fc30000000-fc300fffff memory: f6a00000-f6a07fff
Ok, let's try:
lspci -nn | grep -i network
And see if that ID's the device itself at the PCI level...
Aight.
0b: 00.0 Network controller [0280]: MEDIATEK Corp. Device [14c3:7902]
This card Mediatek 7902 is not support in Linux.
That should be in the default kernel.
Is Secure Boot enabled in your BIOS settings?
It can block some Linux drivers.
It has been pulled into the later kernels, now that Zorin OS 18 is released - it should have access to the module.
How can I disable secure boot? It only gives me option like OS type and Secure boot mode.
I didn't found any reports that it works now. Here it is not listed.
There are only experimental repositories for developing a linux driver for mediathek 7902 on github:
Under OS type, select "Other"; For Secure Boot Mode, select "Custom" and clear the Secure Boot keys - that should disable it.
We can check:
@BOUBERT , please relay the terminal output for:
lspci -nnk -d 14c3:7902
If the module is listed, but is not binding, we know it is supported in the kernel.
This is what appears
Ob:00.0 Network controller [0280]: MEDIATEK Corp. Device [14c3:7902]
Subsystem: AzureWave Device [1q3b:6040]
Should the secure boot keys also be deleted if BOUBERT also has Windows on his computer?
I do not. This is a completely fresh computer with no OS on it before installing Zorin
Good Question. Thanks for bringing that up. I got caught up in problem solving and focused on that...
For: lspci -nnk -d 14c3:7902?
That would be an unusual output...
I only typed what you asked. I really don’t know anything else about this.
It’s what appeared after typing it. Yeah.
I really don’t know anything about complex PC stuff. I’m really feeling down.
Understandably.
It appears that @Forpli is correct and I was operating under misinformation.
Your output can only mean that there is no module in the kernel, for your wifi card, at all.
What you can do, though, is grab an inexpensive Wifi dongle that has Linux support.
EDIT: I am seeing it listed in the Modules Extra package, though - which is why I think it has support.
Let's check anyway, @BOUBERT (tahnks for the patience), can you run:
apt policy linux-modules-extra-$(uname -r)
and relay the results?
Linux-modules-extra-6.14.0-33-generic:
Installed: 6.14.0-33.33~24.04.1
Candidate: 6.14.0-33.33~24.04.1
Version table:
*** 6.14.0-33.33~24.04.1 100
100 /var/Lib/dpkg/status
Does it mean a WiFi dongle could work to replace the antenna that comes with my motherboard?
Yes, you can just use the dongle, instead.