You may need to run in terminal
sudo apt update
First for it to see the change.
That said, the Zorin Disk can act as a source for installations, but only by what it contains on it. This is not as goofy as it sounds; as it can contain quite a lot that may not be installed on your system (Much is in place on the disk in case a wide variety of machines need that component) or to fix a file that corrupted during installation.
That said, FrenchPresses tips look the better way to go right now. 
I did not know such use for the installation disk.
I take it for granted that I always have an internet connection and never occurred to me to use installer as a source.
Yes, as soon as he said he had no connection at all on that machine, I was a bit apprehensive. Usually some facet works, or there is a wireless adapter they can plug in. No net at all really increases the troubleshooting and repair difficulty. Trying to switch back and forth from one machine to another using a USB stick... referencing things on a phone...
I really hope the driver you found does the trick on the first try.
edit: maybe phone hotspot...?
That is why I strongly recommend people to have an [inexpensive] USB WiFi dongle for emergency. My feeling is that if anyone can afford the computer those dongles are fraction of the cost of the computer.
It is deb, not dev file.
And sorry, I pasted the wrong link:
Hmmmm... that page says
e1000-x.x.x.tar.gz driver supports all Intel® 8254x-based PCI
What happens if you enter into terminal:
sudo modprobe e1000e
inxi -Fx
System: Host: alex-linxpc Kernel: 5.4.0-45-generic x86_64 bits: 64 gcc: 7.5.0
Desktop: Gnome 3.30.2 (Gtk 3.22.30-1ubuntu4) Distro: Zorin OS 15.3
Machine: Device: desktop System: ASUS product: N/A serial: N/A
Mobo: ASUSTeK model: PRIME B560M-A v: Rev 1.xx serial: N/A
UEFI: American Megatrends v: 0403 date: 01/26/2021
Battery hidpp__0: charge: N/A condition: NA/NA Wh
model: Logitech M720 Triathlon Multi-Device Mouse status: Discharging
hidpp__1: charge: N/A condition: NA/NA Wh
model: Logitech K850 Performance Wireless Keyboard status: Discharging
CPU: 8 core 11th Gen Intel Core i7-11700F (-MT-MCP-) arch: N/A cache: 16384 KB
flags: (lm nx sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx) bmips: 39936
clock speeds: max: 4800 MHz 1: 800 MHz 2: 800 MHz 3: 800 MHz 4: 800 MHz 5: 800 MHz 6: 862 MHz
7: 800 MHz 8: 800 MHz 9: 800 MHz 10: 800 MHz 11: 800 MHz 12: 800 MHz 13: 1326 MHz 14: 1211 MHz
15: 1363 MHz 16: 888 MHz
Graphics: Card: NVIDIA GP107 [GeForce GTX 1050 Ti] bus-ID: 01:00.0
Display Server: x11 (X.Org 1.20.8 ) drivers: nvidia (unloaded: modesetting,fbdev,vesa,nouveau)
Resolution: 1920x1080@60.00hz, 1920x1080@60.00hz
OpenGL: renderer: GeForce GTX 1050 Ti/PCIe/SSE2 version: 4.6.0 NVIDIA 450.66 Direct Render: Yes
Audio: Card-1 NVIDIA GP107GL High Definition Audio Controller driver: snd_hda_intel bus-ID: 01:00.1
Card-2 Intel Device 43c8 driver: snd_hda_intel bus-ID: 00:1f.3
Card-3 Microsoft LifeChat LX-3000 Headset driver: USB Audio usb-ID: 001-003
Sound: Advanced Linux Sound Architecture v: k5.4.0-45-generic
Network: Card: Intel Device 15fa bus-ID: 00:1f.6
IF: N/A state: N/A speed: N/A duplex: N/A mac: N/A
Drives: HDD Total Size: 2512.5GB (24.2% used)
ID-1: /dev/nvme0n1 model: ADATA_SX8200PNP size: 512.1GB
ID-2: /dev/sda model: TOSHIBA_HDWD110 size: 1000.2GB temp: 34C
ID-3: USB /dev/sdb model: HD103SI size: 1000.2GB temp: 0C
Partition: ID-1: / size: 362G used: 13G (4%) fs: ext4 dev: /dev/sdb6
RAID: No RAID devices: /proc/mdstat, md_mod kernel module present
Sensors: System Temperatures: cpu: 33.0C mobo: N/A gpu: 1.0:33C
Fan Speeds (in rpm): cpu: N/A
Info: Processes: 371 Uptime: 6 min Memory: 1983.4/15871.4MB Init: systemd runlevel: 5 Gcc sys: 7.5.0
Client: Shell (bash 4.4.201) inxi: 2.3.56
This Network adapter gained support in kernel 5.5 and higher...
Upgrading your kernel may do the trick...
To install:
Download each .deb file and transfer to a USB.
Plug the USB into your computer without networking and move all three files to your home Downloads folder.
In your terminal, change directory to downloads
cd ~/Downloads
Then enter in:
dpkg -i *.deb
The * sign should cause all three .deb packages to install in order in one command.
Double-post: Please see above for Kernel Pointers.
Afterthought: Your hardware would be well supported in Zorin 16; though Zorin OS 16 Ultimate is still in development. Even so, it may be worth testing for you to try out since you are on a fresh clean install, anyway...
https://sourceforge.net/projects/zorin-os/files/16/beta/Zorin-OS-16-Core-Beta-64-bit.iso/download?use_mirror=phoenixnap
IF that works well and properly, let's message the ZorinGroup to see about refunding your purchase of Zorin OS 15.3 Ultimate that you may choose to either hold for the Z16 Ultimate Release or donate to the team, instead:
Since you're already downloading to your phone, you could plug it into your computer instead of trying to transfer to usb, which doesn't always work or can be a pain, then transfer it straight to your hard drive. Zorin supports a large number of mobile devices and may not need a driver install. Moving the installers multiple times also provides opportunity for data corruption, even through no fault of your own.
Hello！I also meet a similar question in wired connection.Is the problem solved?
Welcome to the forum 233barbecue.
As every machine is different, would you mind giving us a little information about yours? Are you using zorin 16 or 15.3, core, lite or education? Do you have nvidia graphics or radeon? Is your processor Intel or amd and which model? These things may not seem related but every piece interacts and has side effects that you may not consider. Also, have you tried anything to get it working or searched elsewhere for answers... it saves us from giving you the same information and the ever loathed, that didn't work.
hello
i've the same problem of not being able to connect the wired internet
thanks and love
Hi and welcome to the forum 
Can you post the output of this command?
lspci
hello!
YES
This is your Ethernet module:
Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 0c)
I wonder if you need a driver for this.
Lemme look around.
[edit]
This should be the right driver:
https://ubuntu.pkgs.org/20.04/ubuntu-universe-amd64/r8168-dkms_8.048.00-1_all.deb.html
With r8168-dkms everything is working fine!
tnx
but how to install?
Download .deb file.
In file manager you can double click on it to install.
[edit]
Actually, this one is easier.
# sudo apt-get update
# sudo apt-get install r8168-dkms
i'm not sure how to download it with the browser
can i do sudo apt-get install r8168-dkms too?
tnx
i saw your eddit