Error retrieving registry value with Powershell - powershell

Question

I'm attempting to read a value from a registry entry with Powershell. This is fairly simple, however, one particular registry key is giving me trouble.
If I run the following, I can't get the value of the (default) of "$setting".
C:\Program Files\PowerGUI> $setting = Get-ItemProperty -Path "HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion\IniFileMapping\Autorun.inf"
C:\Program Files\PowerGUI> $setting
PSPath : Microsoft.PowerShell.Core\Registry::HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\
CurrentVersion\IniFileMapping\Autorun.inf
PSParentPath : Microsoft.PowerShell.Core\Registry::HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\
CurrentVersion\IniFileMapping
PSChildName : Autorun.inf
PSDrive : HKLM
PSProvider : Microsoft.PowerShell.Core\Registry
(default) : #SYS:DoesNotExist
Normally, I would do $setting.Attribute, or $setting.(default). However, that results in the following error:
C:\Program Files\PowerGUI> $setting.(default)
The term 'default' is not recognized as a cmdlet, function, operable program, or script file. Verify the term and try again.
At :line:1 char:17
+ $setting.(default <<<< )
How do I get the value of the "(default)" attribute?
Thanks in advance.

Answer 1

EDIT Had to look through and old script to figure this out.
The trick is that you need to look inside the underlying PSObject to get the values. In particular look at the properties bag
$a = get-itemproperty -path "HKLM:\Some\Path"
$default = $a.psobject.Properties | ?{ $_.Name -eq "(default)" }
You can also just use an indexer instead of doing the filter trick
$default = $a.psobject.Properties["(default)"].Value;

Answer 2

Another version:
(Get-ItemProperty 'HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion\IniFileMapping\Autorun.inf').'(default)'

Answer 3

Use Get-Item to get an object representing the registry key:
PS > $regKey = Get-Item HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion\IniFileMapping\Autorun.inf
This gives you an instance of RegistryKey. RegistryKey has a method named GetValue; if the argument to GetValue is the empty string (''), then it will return the (default) value:
PS > $regKey.GetValue('')
Why is this better than Get-ItemProperty? It extends more naturally to Get-ChildItem. Get-ChildItem will give you a list of RegistryKey objects. In my particular case, I wanted to list the install paths of the versions of Python installed on my machine:
PS C:\> get-childitem HKLM:\SOFTWARE\Wow6432Node\Python\PythonCore\*\InstallPath `
>> | foreach-object { $_.GetValue('') }
C:\Python26\ArcGIS10.0\
C:\Python\27\