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Create an ISO file with PowerShell!

I received a request at work to transfer 5+gb from the internal network, to a server in the DMZ.  Our DMZ networks are locked down, so I cannot copy the files directly.  I have the trial version of UltraISO that I’ve used for tasks like this in the past, but it’s limited to 300mb in the trial version.  Previously, we’ve used a “swing VMDK” that we’d mount on an internal VM, copy the data to it, take this VMDK and download it to my PC with something like WinSCP, then upload it to a DMZ datastore, mount it to the VM, etc.  This can get messy, especially if you don’t remember to remove and delete the “swing VMDK”.

I decided to do some research online to see if I could use something like 7-zip or another tool to create the ISO.  I happened upon a function that someone wrote for PowerShell to create an ISO via Microsoft’s Technet Script Center. I took the function, read through it to verify it wasn’t going to do anything malicious (which you should ALWAYS do before just blatantly running someone else’s code) and decided to try it.

Here’s the function itself:

function New-IsoFile  
  <# .Synopsis Creates a new .iso file .Description The New-IsoFile cmdlet creates a new .iso file containing content from chosen folders .Example New-IsoFile "c:\tools","c:Downloads\utils" This command creates a .iso file in $env:temp folder (default location) that contains c:\tools and c:\downloads\utils folders. The folders themselves are included at the root of the .iso image. .Example New-IsoFile -FromClipboard -Verbose Before running this command, select and copy (Ctrl-C) files/folders in Explorer first. .Example dir c:\WinPE | New-IsoFile -Path c:\temp\WinPE.iso -BootFile "${env:ProgramFiles(x86)}\Windows Kits\10\Assessment and Deployment Kit\Deployment Tools\amd64\Oscdimg\efisys.bin" -Media DVDPLUSR -Title "WinPE" This command creates a bootable .iso file containing the content from c:\WinPE folder, but the folder itself isn't included. Boot file can be found in Windows ADK. Refer to IMAPI_MEDIA_PHYSICAL_TYPE enumeration for possible media types: .Notes NAME: New-IsoFile AUTHOR: Chris Wu LASTEDIT: 03/23/2016 14:46:50 #>  
    [parameter(Position=1,Mandatory=$true,ValueFromPipeline=$true, ParameterSetName='Source')]$Source,  
    [parameter(Position=2)][string]$Path = "$env:temp\$((Get-Date).ToString('yyyyMMdd-HHmmss.ffff')).iso",  
    [ValidateScript({Test-Path -LiteralPath $_ -PathType Leaf})][string]$BootFile = $null, 
    [string]$Title = (Get-Date).ToString("yyyyMMdd-HHmmss.ffff"),  
  Begin {  
    ($cp = new-object System.CodeDom.Compiler.CompilerParameters).CompilerOptions = '/unsafe' 
    if (!('ISOFile' -as [type])) {  
      Add-Type -CompilerParameters $cp -TypeDefinition @' 
public class ISOFile  
  public unsafe static void Create(string Path, object Stream, int BlockSize, int TotalBlocks)  
    int bytes = 0;  
    byte[] buf = new byte[BlockSize];  
    var ptr = (System.IntPtr)(&bytes);  
    var o = System.IO.File.OpenWrite(Path);  
    var i = Stream as System.Runtime.InteropServices.ComTypes.IStream;  
    if (o != null) { 
      while (TotalBlocks-- > 0) {  
        i.Read(buf, BlockSize, ptr); o.Write(buf, 0, bytes);  
      o.Flush(); o.Close();  
    if ($BootFile) { 
      if('BDR','BDRE' -contains $Media) { Write-Warning "Bootable image doesn't seem to work with media type $Media" } 
      ($Stream = New-Object -ComObject ADODB.Stream -Property @{Type=1}).Open()  # adFileTypeBinary 
      $Stream.LoadFromFile((Get-Item -LiteralPath $BootFile).Fullname) 
      ($Boot = New-Object -ComObject IMAPI2FS.BootOptions).AssignBootImage($Stream) 
    Write-Verbose -Message "Selected media type is $Media with value $($MediaType.IndexOf($Media))" 
    ($Image = New-Object -com IMAPI2FS.MsftFileSystemImage -Property @{VolumeName=$Title}).ChooseImageDefaultsForMediaType($MediaType.IndexOf($Media)) 
    if (!($Target = New-Item -Path $Path -ItemType File -Force:$Force -ErrorAction SilentlyContinue)) { Write-Error -Message "Cannot create file $Path. Use -Force parameter to overwrite if the target file already exists."; break } 
  Process { 
    if($FromClipboard) { 
      if($PSVersionTable.PSVersion.Major -lt 5) { Write-Error -Message 'The -FromClipboard parameter is only supported on PowerShell v5 or higher'; break } 
      $Source = Get-Clipboard -Format FileDropList 
    foreach($item in $Source) { 
      if($item -isnot [System.IO.FileInfo] -and $item -isnot [System.IO.DirectoryInfo]) { 
        $item = Get-Item -LiteralPath $item 
      if($item) { 
        Write-Verbose -Message "Adding item to the target image: $($item.FullName)" 
        try { $Image.Root.AddTree($item.FullName, $true) } catch { Write-Error -Message ($_.Exception.Message.Trim() + ' Try a different media type.') } 
  End {  
    if ($Boot) { $Image.BootImageOptions=$Boot }  
    $Result = $Image.CreateResultImage()  
    Write-Verbose -Message "Target image ($($Target.FullName)) has been created" 

With that, I was able to create a variable for my source data, and use get-childitem to get that location and pipe that to creating the ISO. See below:

$source_dir = "Z:\Install\App123"
get-childitem "$source_dir" | New-ISOFile -path e:\iso\app123.iso
Even though the data was only about 5.4gb, there was over 120k files.  When I ran the script, I saw my PS window was “thinking” and when I glanced at my e:\iso folder, it had created the ISO file…  I saw the file was at 0k, so I said to myself, “This is going to error out!”
But I couldn’t have been more wrong!  It exported a file at 5.4gb!  I uploaded the new ISO to an ISO folder on a datastore accessible by the DMZ hosts, mounted it to my VM and BOOM, all my data was there and I was able to copy it!


I hope someone else finds this as useful as I did!


Ben Liebowitz, VCP, vExpert
NJ VMUG Leader

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