# ISO image - replace with path to ISO to be mounted
$isoImg = "D:\en_visio_professional_2019_x86_x64_dvd_3b951cef.iso"
# Drive letter - use desired drive letter
$driveLetter = "Y:"
# Mount the ISO, without having a drive letter auto-assigned
$diskImg = Mount-DiskImage -ImagePath $isoImg -NoDriveLetter
# Get mounted ISO volume
$volInfo = $diskImg | Get-Volume
# Mount volume with specified drive letter (requires Administrator access)
mountvol $driveLetter $volInfo.UniqueId
#
#
# Do work (e.g. MS Office installation - omitted for brevity)
#
#