VM Created from Image with Azure Powershell does not set ComputerName

Question

I have an Azure Image, which when I use Azure Powershell to create a VM from, despite me setting the ComputerName in the script, the VM is created without setting the ComputerName to the provided value.

Script:

$ImageName = 'MyImage'
$RsgName = 'MyRsg'
$VmName = 'MyNewVM'
$DiagnosticStorageName = 'diagnosticsstore5048'

$cred = Get-Credential -Credential 'TheAdmin'

$Image = Get-AzureRmImage -ImageName $ImageName -ResourceGroupName $RsgName

# Get NIC
$nic = Get-AzureRmNetworkInterface -ResourceGroupName $RsgName

# Configure the new VM
$Vm = New-AzureRmVMConfig -VMName $VmName -VMSize 'Standard_A2_v2'
$Vm = Set-AzureRmVMSourceImage -VM $Vm -Id $Image.Id
$Vm = Set-AzureRmVMOSDisk -VM $Vm -Name $VmName'-disk' -StorageAccountType 'StandardLRS' -DiskSizeInGB '128' -CreateOption FromImage -Caching ReadWrite
$Vm = Add-AzureRmVMNetworkInterface -VM $Vm -Id $nic.Id
$Vm = Set-AzureRmVMBootDiagnostics -VM $Vm -Enable -ResourceGroupName $RsgName -StorageAccountName $DiagnosticStorageName
$Vm = Set-AzureRmVMOperatingSystem -VM $Vm -Windows -ComputerName 'dor' -Credential $Cred -ProvisionVMAgent

New-AzureRmVM -VM $Vm -ResourceGroupName $RsgName -Location 'West Europe' -DisableBginfoExtension

Last time I run the script to create the VM, it left the new VM with a computer name of 'WIN-I80O6J22ENS' The Image was created as per the process here: https://docs.microsoft.com/en-gb/azure/virtual-machines/windows/capture-image-resource?toc=%2Fazure%2Fvirtual-machines%2Fwindows%2Fclassic%2Ftoc.json

UPDATE Alot of people think that I am not Generalizing the image correctly, so I wanted to add here how I am doing it. Inside the VM I run:

Start-Process -FilePath $env:windir\System32\Sysprep\Sysprep.exe -ArgumentList "/generalize /oobe /shutdown /unattend:$env:windir\System32\Sysprep\unattend.xml"

Unattend.xml only has one setting in it which is to step the TimeZone.

Once this is completed and the VM OS has shut down, I run the following to get the VM, stop it, and set it to Generalized:

# Shutdown Source VM & Generalize
$SourceVM = Get-AzureRmVM -ResourceGroupName $SourceRsg -Name $SourceVMName
$Null = Stop-AzureRMVM -ResourceGroupName $SourceRsg -Name $SourceVMName -Force
Write-Host 'Stopped Source VM'

Set-AzureRmVm -ResourceGroupName $SourceRsg -Name $SourceVMName -Generalized
Write-Host 'Set Source VM to Generalized'

I have noticed that when the last command is ran, the output is:

OperationId :
Status :
StartTime :
EndTime :
Error :

It doesn't actually say if it was successful or not?

Answer 1

It might be caused by the image not being "Generalized".

1. Create some variables.

   $vmName = "myVM" $rgName = "myResourceGroup" $location = "EastUS" $imageName = "myImage"

2. Get the VM.

         $vm = Get-AzVm -Name $vmName -ResourceGroupName $rgName

3. Get the ID of the managed disk.

$diskID = $vm.StorageProfile.OsDisk.ManagedDisk.Id

Create the image configuration.

$imageConfig = New-AzImageConfig -Location $location $imageConfig = Set-AzImageOsDisk -Image $imageConfig -OsState Generalized -OsType Windows -ManagedDiskId $diskID

4. Create the image

New-AzImage -ImageName $imageName -ResourceGroupName $rgName -Image $imageConfig

Learn how to move an Azure VM image to another resource group here.