Hyper-V install script

[axelfontaine]

What do you need?

Before trying Omarchy on real hardware, I decided to kick the tires using Hyper-V. I believe many other Windows users will follow a similar adoption path.

I created the following automated install script that sets up the entire VM, disks, boot order, resolution, ... from scratch and drops you into a window with the Omarchy install already running:

# Exit on first error
$ErrorActionPreference = "Stop"
trap {
    Write-Error "Error: $($_.Exception.Message)"
    exit 1
}

# Variables
$isoUrl     = "https://iso.omarchy.org/omarchy-3.0.1.iso"
$vmName     = "Omarchy"
$switchName = "ExternalSwitch"

# Path where to store everything
$vmHost  = Get-VMHost
#$vmPath  = $vmHost.VirtualMachinePath # Hyper-V VM directory
$vmPath  = (Get-Location).Path #Current Directory
$vhdPath = Join-Path $vmPath "$vmName.vhdx"
$isoPath = Join-Path $vmPath "$vmName.iso"

# Create folders
New-Item -ItemType Directory -Force -Path (Split-Path $isoPath) | Out-Null
New-Item -ItemType Directory -Force -Path $vmPath | Out-Null

# Download ISO (skip if already exists)
if (-not (Test-Path $isoPath)) {
    Write-Host "Downloading ISO from $isoUrl ..."
    Start-BitsTransfer -Source $isoUrl -Destination $isoPath
    Write-Host "ISO downloaded to $isoPath"
} else {
    Write-Host "ISO already exists at $isoPath — skipping download"
}

# Get total system memory in bytes
$totalRAM = (Get-CimInstance -ClassName Win32_ComputerSystem).TotalPhysicalMemory
# Half of system RAM in MB, rounded down to nearest whole MB
$halfRAMMB = [math]::Floor(($totalRAM / (1024*1024)) / 2)  # Convert bytes to MB
# Align to 4 MB boundary (Hyper-V prefers multiples of 4)
$alignedRAM = [math]::Floor($halfRAMMB / 4) * 4 * 1024 * 1024

# Check if VM already exists
if (Get-VM -Name $vmName -ErrorAction SilentlyContinue) {
    Write-Host "VM '$vmName' already exists — skipping creation."
} else {
    # Create VM
    New-VM -Name $vmName -MemoryStartupBytes 1GB -Generation 2 -Path $vmPath
    Set-VMMemory -VMName $vmName -DynamicMemoryEnabled $true -MinimumBytes 1GB -MaximumBytes $alignedRAM
    Write-Host "VM '$vmName' created at $vmPath"
}

# Create VHD (skip if it already exists)
if (-not (Test-Path $vhdPath)) {
    New-VHD -Path $vhdPath -SizeBytes 64GB -Dynamic | Out-Null
    Add-VMHardDiskDrive -VMName $vmName -Path $vhdPath
    Write-Host "VHD created at $vhdPath"
} else {
    Write-Host "VHD already exists at $vhdPath — skipping creation"
}

# Check if VHD is already attached
if (-not (Get-VMHardDiskDrive -VMName $vmName | Where-Object { $_.Path -eq $vhdPath })) {
    Add-VMHardDiskDrive -VMName $vmName -Path $vhdPath
    Write-Host "VHD attached."
} else {
    Write-Host "VHD is already attached — skipping."
}

# Check if ISO is already attached
if (-not (Get-VMDvdDrive -VMName $vmName | Where-Object { $_.Path -eq $isoPath })) {
    Add-VMDvdDrive -VMName $vmName -Path $isoPath
    Write-Host "ISO attached."
} else {
    Write-Host "ISO is already attached — skipping."
}

if (-not (Get-VMSwitch -Name $switchName -ErrorAction SilentlyContinue)) {
    New-VMSwitch -Name $switchName -NetAdapterName "Ethernet" -AllowManagementOS $true
    Write-Host "Created VMSwitch '$SwitchName'"
} else {
    Write-Host "VMSwitch '$SwitchName' already exists."
}
Connect-VMNetworkAdapter -VMName $vmName -SwitchName $switchName

# Disable Secure Boot (needed for unsigned Linux ISOs)
Set-VMFirmware -VMName $vmName -EnableSecureBoot Off

# Get the current boot order
$firmware = Get-VMFirmware -VMName $vmName

# Get the devices
$vhdDevice = $firmware.BootOrder | Where-Object { $_.Device -is [Microsoft.HyperV.PowerShell.HardDiskDrive] }
$cdDevice  = $firmware.BootOrder | Where-Object { $_.Device -is [Microsoft.HyperV.PowerShell.DvdDrive] }

# Set the boot order: VHD first, then DVD
Set-VMFirmware -VMName $vmName -BootOrder $vhdDevice, $cdDevice

# Enable Enhanced Session Mode (host + user)
Set-VMHost -EnableEnhancedSessionMode $true

# Detect host resolution and apply it to VM video
Add-Type -AssemblyName System.Windows.Forms
$screen = [System.Windows.Forms.Screen]::PrimaryScreen
$width  = $screen.Bounds.Width
$height = $screen.Bounds.Height
Set-VMVideo -VMName $vmName -HorizontalResolution $width -VerticalResolution $height -ResolutionType Single
Write-Host "Set VM resolution to $width x $height"

# Start the VM
Start-VM -Name $vmName
Write-Host "VM $vmName started."

# Open the VM console window
$vmConnectPath = "$env:SystemRoot\System32\vmconnect.exe"
Start-Process $vmConnectPath -ArgumentList "localhost", $vmName

More work is needed inside the VM in the future, as Hyper-V should be detected and then Enhanced Session should be automatically set up. But that can be done separately, along with the other hardware-specific parts of the Omarchy installer.

I'm posting this script here as I didn't know where a good fit would be. Putting it behind a one-liner on the Omarchy homepage or manual that can be pasted directly into Windows Terminal is probably the best place.

[atiqsamtia]

I was stuck on VMWare from months and wasted many hours trying to make Omarchy work but could not fully. This script is a lifesaver and worked like a charm.
One note, when copying the script from here and pasting inside ps1 file. Error messages in this script containing ' — ' breaks the script due to maybe font issue. had to fix those locally and then it worked well. error message like "ISO already exists at $isoPath — skipping download"

[dheemadd]

[axelfontaine]

Please don't. The original script does not need to be run as an administrator, does not need the ISO to be ejected, ... This only adds confusion and doesn't fix any actual shortcomings like the lack of Enhanced Session. Please focus your efforts on fixing those instead. Thanks.

[dheemadd]

Sure mb

[jordankoehn]

I get this error when running the PS1 script

At C:\Users\Jordan\Downloads\omarchy-install.ps1:113 char:56
+ # Start-Process $vmConnectPath -ArgumentList "localhost", $vmName
+                                                        ~~~~~~~~~~
The string is missing the terminator: ".
At C:\Users\Jordan\Downloads\omarchy-install.ps1:71 char:8
+ } else {
+        ~
Missing closing '}' in statement block or type definition.
    + CategoryInfo          : ParserError: (:) [], ParseException
    + FullyQualifiedErrorId : TerminatorExpectedAtEndOfString

I was able to get it installed by manually running the lines. Graphical performance is very slow, is this related to lack of enhanced sessions? When reading about enhanced sessions in the arch wiki, it's targeted at X11 based installs. You implied you were able to get it set up in wayland?