This is probably because you installed Ubuntu in a different mode than Windows. If your device came pre-installed with Windows, I will assume it was installed using EFI mode, with fast startup enabled.
You will need to first make your Windows installation work (i.e. boot) again, then re-install Ubuntu using the same installation mode as Windows.
To do that, boot into your BIOS and change boot order, so "Windows Boot Loader" is the first. If you changed from EFI boot to legacy, change it back. If you disabled fast startup you may need to re-enable it (not necessarily, some installations will work regardless).
Once Windows is working, remove Ubuntu completely, by deleting the partition completely, and then remove grub from Windows boot loader.
When you are done with that, re-install Ubuntu using the same installation mode as Windows.
Note: you will need to use partition editing techniques and other methods that require some understanding and experience. Only follow the above suggestion if you know how to use these tools.
The Zorin 16 installer no longer supports 32bit architectures, so no longer supports MBR. It may be possible to set the bios to legacy mode, and that may resolve the issue. Having the drive set up with both MBR and GPT will cause a conflict when Windows is installed as 32 bit on MBR style disks. The solution that will definitely work is to either reinstall windows as 64bit in GPT style or go without Zorin.
There is a possibility you can find a custom script to boot in AHCI or RAID depending on the OS chosen, but this isn't something you will find easily. I have only ever seen one custom boot script to get an NVMe to work. Another option is to purchase a newer laptop, funds allowing.
