Installing

Mizu starts from a USB stick and can stay there. Installing it onto a disk is a choice you make later, from inside it.

What it needs

A 64-bit PC that boots with UEFI. Old BIOS-only machines are not supported.
Secure Boot off: Mizu's loader is not signed by Microsoft.
2 GB of memory is plenty; a USB stick of 1 GB or more.
For the network, a wired Intel card or USB tethering from a phone. There is no Wi-Fi yet.

From a USB stick

Download mizu-1.0-preview.img.zip from Releases and unzip it.
Write the image to the stick with Rufus (DD image mode) or balenaEtcher. Everything on the stick is replaced.
Start the PC from the stick: the boot menu key is usually F12, F11, F8 or Esc at power on.

The first start opens Mizu Setup: a language, the clock, your name, and if you like a password or a PIN. A minute later you are on the desktop, and everything you do is kept on the stick.

Onto a disk

Start > System Tools > Install Mizu...

Choose the disk. The one Mizu is running from is never offered.
Choose the whole disk, or only its free space. With free space, Windows or Linux on the disk stay as they are; Mizu creates its partitions in the space nobody uses. To make room, shrink the other system's partition with its own tools first.
Say how many gigabytes Mizu gets, check the partition table before and after, and confirm.
Click Restart with the stick still in. The computer's boot menu gets a "Mizu" entry by itself; from then on Mizu starts from the disk.

An existing EFI system partition is reused and never formatted: Mizu's loader goes in beside the others. If that partition is too small, Setup says so and stops.

In a virtual machine

VirtualBox

New machine, type Other, version Other/Unknown (64-bit), 2 GB of memory. In System, tick Enable EFI. Attach mizu-1.0-preview.vdi to the SATA controller.

QEMU

qemu-system-x86_64 -enable-kvm -m 2G -machine q35 -smp 4 \
  -drive if=pflash,format=raw,readonly=on,file=/usr/share/edk2/ovmf/OVMF_CODE.fd \
  -drive format=raw,file=mizu-1.0-preview.img \
  -device qemu-xhci -device usb-mouse -device usb-kbd \
  -device e1000e,netdev=n -netdev user,id=n -device intel-hda -device hda-output

How the disk is laid out

Part	What is on it
EFI system partition	The loader, and which system slot to start (FAT32).
Slots A and B	The system itself, a read-only SquashFS image, seen as `Z:\MIZU`. One runs, the other takes the next update.
Data	Your files and settings, on KFS, as `Z:`. Never rolled back.

Using Mizu →