Sadly.... chuckle... this is a point of contention about 15.3 that we have all raised: There really isn't an easy way.
Most of us can tell by looking at the desktop but, for someone new to Linux, it is not that recognizable.
Please open a Terminal and type in
nautilus
If files launches, you have Core.
In terminal enter in
xfce4-appfinder
If it says, "Not installed but can be installed with..." - then you have Core.
Just typed in nautilus. Files did appear with a popup - "oops, something went wrong. Unable to create a required folder...
and in the terminal, a variety of warnings appeared
just typed in the second command and it says command 'xfce4-appfinder' not found but can be installed with:
So this means they used core... could this be the cause of my problems? The refurbisher failed to choose the correct zorin?
It... actually could.
The Random Freeze is far more prevalent in the Gnome-Shell (What Core uses) on certain machines than it is on the XFCE desktop.
And on those machines, I would definitely recommend the Lighter Desktop. Gnome is not more advanced than XFCE and XFCE has all the same (if not more in my opinion) functionality.
Is reinstallation an option for you? That is a lot of machines...
Oh goodness, yes that will be a lot of work. Yes, it is an option but I'll be putting a few late nights in at the school. I've got some required apps too which will need to be reinstalled (chrome, arduino ide). Just checking, there isn't a way to change OS versions without reinstalling? (I'm guessing no... 'weeps in corner')
I'm wondering if 16 core would be beneficial. Zorin's made 16 better than 15.3, faster and even though gnome can be resource intensive, may not be as much... from my experience. Though it would be a process to get every laptop setup, 16 with cinnamon might be the best bet. You could always try one of each model and if they are stable, expand to the rest.
I can definitely try mixing for experiment's sake. Excuse my lack of knowledge (im pretty new) what is cinnamon? (in relation to linux)
Ah, I don't agree.
XFCE is as lightweight as LXDE is.
Cinnamon is heavier than XFCE, but lighter than Gnome.
tbuller, on Windows, you have one desktop environment: Windows.
On Linux... There are many. Many to choose from and each has its pros and its cons.
This type of variety is a beautiful thing but it can be overwhelming when you first encounter it.
What about replacing only the Troublesome (freezing) computers?
Lastly... Sorry Harvey but I disagree again... Zorin OS 16 Core is indeed fast with much improvements made on performance, just as 15.3 was much faster than Zorin OS 12.4 was. But... These are in relation to the previous Core (Gnome) desktops. On these older machines, it wouldn't really be that much benefit and may be worse. I have two similar spec machines here.
Even improved Zorin 16 Core is not going to perform better or faster than Lite on a low spec machine.
Thank you very much for taking the time to explain things. Fingers crossed, some of my tech-ier students won't mind helping me through the process now, and then again when education lite 16 makes its debut. After converting, if I'm still having similar issues, I'll return to this thread and perhaps there will be some clues in the logs. But fingers crossed doing this changeover makes all the difference. Thank you again!
Or Zorin OS 16 Gamer Edition 
. Instant download for me 
Throw that in Feedback Forum... If Z.G. goes for it, it would probably be a smash hit.
$40 for Zorin Pro.
$70 for Zorin Gamer Edition.
Hello again,
So I changed out my computers to lite the other day (with help from a couple students). Although slightly less, I still am getting instances of freezing. Sometimes while a computer is awake, other times when the computer goes into sleep (suspend...i think), the fan goes nuts and it won't wake up.
Here are those logs you asked me for before:
If you have time, please let me know if something is up and what I might be able to do to fix this.
Thank you!!
Neither logs show anything I can find that would explain freezing, segfaults or crashing...
How many machines are affected?
On the affected machines, are you running any Google Chrome?
The Logfile you sent showed AMD graphics. Are any affected machines using Nvidia?
One possibility may be that affected machines may need their BIOS updated.
I hope this is only on one computer- because this usually means a hardware fault within the RAM.
Yesterday, I had perhaps 5 affected computers... though, it isn't always the same computer. They are mostly the same model with the same specs.
I do have google chrome installed - our school uses google classroom to post assignments, so I assumed it was fitting to install that browser.
As far as I'm aware, my computers are not using Nvidia
Is the best way to update BIOS on linux to go to the Toshiba or Dell website, or is there an easier method via the terminal?
Thank you for your help.
It depends on the vintage of your laptops.
On older ones, it may be possible to make a bootable DOS USB and update BIOS from there. A newer BIOS could be updated within the BIOS menu. The last category - many newer laptops belong to this - can be updated BIOS in Windows only.
On the affected computers, can you open Chrome, then in a new tab, enter chrome://settings in the address bar.
Select Advanced
Then UNcheck the box for use hardware acceleration when available
In terminal, run
google-chrome --disable-gpu
Thank you both for your suggestions. I will try these things and let you know.
So, I've gone ahead and switched that google chrome setting. I tried to figure out how to update BIOS but haven't figured out how yet. Many websites told me if I do it wrong, I wreck the computer for good, so I'm hesitant.
I am still getting freezing events - some during sleep and some while the computer is being used. Almost every time this happens, the event is paired with the fan going super loud.
I really appreciate all the advice so far. If you have any other ideas I could try, please let me know. I realize we may be hitting a dead end. Is there a way to check for RAM fault as you mentioned in a previous comment?
Thank you!
Yes; a fast and simple way (That I just posted in another thread, in fact) is:
sudo apt install -y memtester
Then test with:
sudo memtester 100M 2
My older Acer Notebook used to get this on Zorin OS 15 Lite, too. None of the other machines ever did - and sometimes, after an update, the freezing-if-sleep went away. Sometimes, it came back after an update.
I never did manage to solve it...
And am now using a Tower, resolving the problem.
It does seem to usually affect notebooks - so probably Lid Switch related or Screensaver related. On a school notebook which is used by many people, I am not sure if setting to ignore lid switch will work out, as they may close the lid and drain the battery completely.
If you do not use Screensaver, then you may try
xset s 0 0