Ubuntu, UEFI and hard disks

[Linux for blind general discussion]

Hello, Birdie here!

> I posted this over at askubuntu but I figured I'd ask here too. Got my
> laptop to boot into Ubuntu Mate. Problem is...it won't detect the hard
> drive at all. I can do slblk and all it shows is dev/sda (which is the
> USB stick). Installer picks up the stick too and tell me I need 8GB of
> space on the 8GB memory stick.

Most likely your problem is that the storage in your new laptop is
not what we know as a hard disk. It could be that it is a solid state 
disk.
If the storage connection is NVMe (Non volatile memory express) it would
show up as /dev/nvme0*. There are also other possible alternatives
depending on connection and storage type. SSD is not the only 
possibility.

Most likely your Ubuntu distribution doesn't understand your laptops
storage controller.

> I went into Win10's settings and turned off UEFI, then secure boot.
> So. Should I reenable the UEFI firmware but leave secure boot off,
> or...?

By all means you should have left the settings intact. All decent
Linux distributions are able to boot with UEFI and secure boot.

Since we don't know anything about your laptop nor your Ubuntu Linux
distribution all this is only speculation.

If you would like to have a better and more educated answer to
your problem please tell as much as possible about the situation.
If you still have Windows installed on the computer you could go to
About this computer and check what kind of storage you have installed.