Hey there,
unfortunately, I know its not tested yet, I updated my driver to the nvidia 565 version via the Software & Update center.
After the restart a couple of programs as well as my internet connection (via cable and WiFi) is not working anymore.
I would like to switch back but can't download the 550 driver, as no internet connection...
What is the best approach for me?
Thanks!
Did you do any updates to the system ? since it is a bit weird a nvidia driver would kill wifi and cable connection. First try to reset your modem and check if internet/connection works.
What is the output from sudo lshw -C network ?
If that does not work then do a manual install for the nvidia driver.
Welcome to the Forum!
Did You install anything or update anything else? Maybe a Kernel Update?
You could uninstall the Driver over the Terminal, check if Your Internet connection runs again and then Install the 550 Driver. To do that, type in the Following:
For uninstall the Nvidia Driver:
sudo apt purge nvidia* libnvidia*
Then:
sudo apt autoremove
But please check what will be deleted before You delete it. After this check if Your Internet connection works and if yes type the following to install the 550 Driver:
sudo apt install nvidia-driver-550
If the problem is on the driver that takes care of the wifi card, you could try using an android phone as a wired access to the wifi, as it will be detected as normal ethernet, and then download the 550 driver with it
if you have an iphone or an older android instead, I'm not sure if it would also work but I'm guessing it would?
It definitely would, I've run into this issue plenty of times. Most (if not all) modern smartphones should have a USB Tethering mode to share the internet connection with a computer through the USB. Saved me plenty of times on older hardware that didn't have anything working by default.
Thank you very much!
@Ponce-De-Leon
Doesnt work... I uninstalled the driver as you said but it seems like Zorin switched automatically to the nouveau open source driver. Still. No internet connection at all...
@Sorro
Very good idea! Tried it myself immediately. Didn't work. My phone supports USB tethering but Zorin did not seem to get any connecting.
Is there any way to reinstall the driver via Zorin live or via the driver as a file? Or any other way? 
That was my Intention that it goes to the Nouveau Drivers to look if the Nvidia Driver causes that. You could take a Look in the ''Additional Drivers'' Tab ind Software & Updates if there beneath the Nvidia Drivers are a Driver for Your Network Card/Chip is offered. Maybe You have to scroll a bit to see it.
Okay ... And when You now install the 550 Driver? But install it over the Terminal, not in the Overview. Open the Terminal and type sudo apt install nvidia-driver-550 and after the Installation make a Reboot and then test if it works.
The error messages point to not being able to connect
I don't have a nvidia card so I don't know if this would work, but what about manually downloading the packages as .deb files from another computer (or a phone) and moving them to this one with a usb thumb drive/phone charger? As long as all dependencies are met, deb packages can usually be installed without internet connection
Please check to make sure whether you have an active network connection or not. At this point I am not talking about internet, I am just talking about the wired connection.
Click 
icon bottom of screen, then click on 
settings. Scroll down the list and click on network
This is what you want to see under wired. This shows that my connection is working. If you don't have that, and it instead says unplugged, it would be a really good idea to power cycle your cable modem and router if you have one.
Has this been addressed?
@JoeHardi , clearly, troubleshooting the net connection is the first priority.
joehardi@JoeHardi:~$ sudo lshw -C network
[sudo] password for joehardi:
*-network UNCLAIMED
description: Ethernet controller
product: Ethernet Controller I225-V
vendor: Intel Corporation
physical id: 0
bus info: pci@0000:08:00.0
version: 03
width: 32 bits
clock: 33MHz
capabilities: pm msi msix pciexpress bus_master cap_list
configuration: latency=0
resources: memory:fc200000-fc2fffff memory:fc300000-fc303fff
*-network UNCLAIMED
description: Network controller
product: MEDIATEK Corp.
vendor: MEDIATEK Corp.
physical id: 0
bus info: pci@0000:09:00.0
version: 00
width: 64 bits
clock: 33MHz
capabilities: pciexpress msi pm cap_list
configuration: latency=0
resources: iomemory:fc0-fbf memory:fc20300000-fc203fffff memory:fc600000-fc607fff
My output from sudo lshw -C network
I double checked. I only see everything you see from VPN downwards. Nothing above.
Nothing happens. As soon as I install the deb package the software center opens and ask if I want to install. I install and nothing happens.
Which VPN? This might narrow down where the trouble is... VPN's are touchy
No VPN activated nor installed. I only meant that is an option within the settings.
What is the output from this ?
sudo dpkg -s linux-modules-extra-$(uname -r) | grep Status
I think linux module extra needs to be reinstalled.
dpkg-query: package 'linux-modules-extra-6.8.0-51-generic' is not installed and no information is available
Use dpkg --info (= dpkg-deb --info) to examine archive files.
Seems like that...
This package is missing and needs to be reinstalled.
Can you check the suggested command ?
Edit: Download this file and place it in your desktop
Run these 2 commands
cd ~/Desktop
sudo dpkg -i linux*.deb