Updating this with a bit more info, using Powershell on Windows 10 (v1703-1809) I was able to reference and set the Folder options registry keys for both Current User and Local machine, with the following code.
The biggest realization for me, not obvious in previous posts, was that the reg key paths for folder-options-related settings are subtly different depending on whether you want to get/set Local Machine or Current User, both in key path consistency and key value access. Also, if not obvious, Current User settings will override Local Machine.
Here is a example code snippet (tested w/ PS 5.1):
## Grab Current User setting(s):
$CUfvHidden = (Get-ItemProperty -Path HKCU:\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced -Name 'Hidden').Hidden
$CUfvHideFileExt = (Get-ItemProperty -Path HKCU:\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced -Name 'HideFileExt').HideFileExt
$CUfvFullPath = (Get-ItemProperty -Path HKCU:\Software\Microsoft\Windows\CurrentVersion\Explorer\CabinetState -Name 'FullPath').FullPath
if ($CUfvHidden -eq 1) { Write-host "CU: Show Hidden set to 'ON'" } #expecting val 1 or 2
else { Write-host "CU: Show Hidden set to 'OFF'" }
if (-not $CUfvHideFileExt) { Write-host "CU: File extensions DISPLAYED" } #expecting val 1 or 0
else { Write-host "CU: File extensions hidden" }
if ($CUfvFullPath) { Write-host "CU: SHOW full path in title bar" } #expecting val 1 or 0
else { Write-host "CU: DO NOT show full path in title bar" }
## Grab Local Machine setting(s)...As you can see the LM reference paths are
## slightly different, to get 1 and 0 values, compared to CU and each other:
$LMfvHidden = (Get-ItemProperty -Path HKLM:\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden\ShowAll).CheckedValue
$LMfvHideFileExt = (Get-ItemProperty -Path HKLM:\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\HideFileExt).CheckedValue
$LMfvFullPath = (Get-ItemProperty -Path HKLM:\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\ShowFullPath).CheckedValue
if ($LMfvHidden) { Write-host "LM: Show Hidden set to 'ON'" } #expecting val 1 or 2
else { Write-host "LM: Show Hidden set to 'OFF'" }
if (-not $LMfvHideFileExt) { Write-host "LM: File extensions DISPLAYED" } #expecting val 1 or 0
else { Write-host "LM: File extensions hidden" }
if ($LMfvFullPath) { Write-host "LM: SHOW full path in title bar" } #expecting val 1 or 0
else { Write-host "LM: DO NOT show full path in title bar" }