How do I get to the grub menu to select an older kernel?

[Aravisian]

Boot into Zorin normally, then open terminal and run:

sudo nano /etc/default/grub

Move to this line: GRUB_TIMEOUT_STYLE=hidden and change the option of "hidden to "menu:"
GRUB_TIMEOUT_STYLE=menu

Ensure the timeout is set to a non-zero number. I will recommend a ten full seconds:
GRUB_TIMEOUT=10

Tap ctl+o to overwrite, then enter to save the current configuration. Tap ctl+x to exit the editor.
The terminal will revert to normal. Now you must run

sudo update-grub

Reboot and test if you can access grub menu and roll back your kernel.
If you can and you need to stay on the older kernel:

[HOW TO] set an older kernel to default boot

You may need to use an earlier kernel than the current kernel used by Zorin. This method allows you to set the kernel that you will boot into by default. To set the new kernel to default: Boot into the kernel you wish to be Saved. Open terminal and run: sudo nano /etc/default/grub Change GRUB_DEFAULT=0 to GRUB_DEFAULT=saved Hit enter to drop down a line. Add GRUB_SAVEDEFAULT=true ctrl+x to exit, then the y key to say yes to save, then the enter key to save as current configuration. Ru…