How do I uninstall Zorin OS 16 on my hp Compaq

I need help uninstalling the Zorin OS 16, I’m trying to go back to windows but I can’t because there’s already a user on there and I can’t log in or do anything right now because the user has a password. I know how to get in the account but I can’t connect to the internet, I can’t add another user, I can’t install anything, I can’t do anything I’ve been trying all day to figure it out, but there’s no way to uninstall it, I want to wipe everything from the computer, and please explain it as simple as possible

This can be done outside of Zorin OS by using Windows Partition Manager to delete the partition that contains Zorin OS and then reformat it.

But what about grub? It remains?

But I can't, I'm stuck using Zorin OS 16 the pc I'm using is (HP-Compaq-Pro-3600-SFF). Like I can't uninstall it, I can't change password, I can't do anything. I don't know how to use or get ubuntu, I know how to use GRUB but I just don't know any commands to factory reset the computer back to windows. And my GRUB menu says (GNU GRUB 2.04). What do I do from there

Unlike Windows, Zorin OS does not lock the drive. So, you do not need to access the Zorin Operating system in order to install Windows. Just boot from the Windows Installer medium and use the Windows Partition Manager, or run the Windows Installer, from the Windows Installation Medium.

Even if you could boot up Zorin OS, it cannot access Windows Software and run it. So you wouldn't be able to recovery Windows in that manner.
Only Windows can do that.

You say the user on Windows has a password - did you install Zorin without the user's consent? Just wondering!

No, the pc was just given to me and already had a user on there

But I didn’t download Zorin OS 16 it was already on pc when I got it

I understand, but this is not relevant. You do not need to Log In on Zorin OS in order to install a different operating system.

The only reason you would need a password would be if the Notebook had the drive LVM Encrypted.