That's 686.
It has "support' for 64bit - this would take some in-depth explaining. But the short short version for this thread is - it is not really 64bit. You would need 32bit.
You would not see much difference in using a newer kernel for that vintage of architecture.
Also, when Zorin 16 Lite is out, there will be a upgrade path.
Oops, I messed that one.
Then OP needs other distro which still supports 32bit architecture in their latest offering - such as MXLinux.
Zorin 16 does not support 32bit arch. The only option is Zorin OS 15.3 lite 32bit.
Yup, I saw that and added some lines in the previous posting.
I don't think ZorinOS Core/Pro 16 has 32-bit version, right? Maybe the future Lite version?
I guess the 32-bit CPU wouldn't be as efficient, or would the OS just not run?
No, Zorin is based on Ubuntu which dropped 32bit support.
So the Lite version will be 64bit only.
Actually I had a close look at the CPU spec.
It says 64bit.
But its BIOS could be 32bit (yes, there is such chimeric system).
You could try booting from 64 bit live USB.
If it boots, then you are lucky.
If not, I can help you to convert 64 bit Ubuntu based OS to be installable on a 32bit BIOS.
I tried the thumb drive live boot for an hour for both Core and Pro, and was stable.
Wow, you're amazing, if you're willing to help me with the conversion.
Then congratulation
you do have a 64 bit system.
Since you have purchased Pro edition, you can ask for installation help directly from Zorin group. Just reply to the email you received after the payment and ask for help. Installation support is included in the price of the Zorin 16 Pro.
Yay!
I need to celebrate.
Good idea. I forgot about the support. 
Actually it is not me who is amazing.
The real brain behind this project is this:
I think you need to format this original 150GB partition using Gparted tool included in the live USB. You will not see the install option till you have a properly formatted partition.
Please be sure all chkdsk, windows fast boot and hibernation are complete and off before proceeding. If you change the partition for windows and windows has a lock on the drive for one of those purposes you'll be installing two os's, not one.
Resize the windows partition leaving about 10gb for play. Updates and software will eat it pretty quickly. The unallocated space that gives you can be formatted ext4 (not in windows... windows can't read ext4) that will be where you put zorin. Overwrite the windows bootloader partition to have the dual boot experience. Beyond that, you should be good. If you do make a mess, install using the gpt/uefi style of possible (may have to upgrade your bios though). If make sure the bios was completely up to date before trying any of this.
I haven't been able to resize my Window10 volume/partition. I need to figure out why. Might be some page file or hibernation files locking it. Need to reconfirm.
Chkdsk completed long ago and have fastboot off. Hibernation was off, but sleep was still on. Windows defragmentation tool mentioned certain files unmovable and left at 3% fragmentation.
Just turned sleep off and will reboot to see if I can manipulate volume size.
There should be nothing for windows to lock the drive for then. You shouldn't have an issue.
Thanks for your help everyone, @Aravisian @FrenchPress @337harvey. I did disc defragmentation another time and got it down to 2% after turning off Sleep in Advanced Power. Then used Paragon Partition Manager to resized Win10 partition down to 103GB with 30% free space in it. Left 50GB space unallocated on the HDD. It finally allowed me to install dual boot. 
I will bother you all again sometime in the near future.
I can hardly wait to help you!
Every single new Zorin user gives a satisfaction to my small ego 
I'll give you one good news: Linux never needs defrag 
In that case, prepare to be bloated! 

