Windows PowerShell Get Registry '(Default)' 'Value Size' and 'Value data'

If I use regedit, I can view Registry 'Computer\HKEY_CURRENT_USER\AppEvents'. The only entry is: Name (Default) Type 'REG_SZ' Data (Value not set)'

If I double-click on the '(Default)' entry: Value name: (Default) Value data: <blank>

I've tried numerous ways to access the 'Type' and 'Data' contents without success.

I've tried using:

(1) $key = Get-Item -Path 'HKCU:\AppEvents'

(2) foreach ($name in $key.GetValueNames())

but this either results in an exception or doesn't get the values.

I've found nothing on the web that has a simple explanation of how to access the '(Default)' type and data values.

Anyone who can provide a simple way to do this? I've tried many ways to get the name and data values.

Solution

Assuming that a given registry key exists, it may or may not have an unnamed value, which regedit.exe represents as (Default) in its GUI.
Similarly, the GUI showing a Data value of (Value not set) implies that this value doesn't exist, so there's nothing to retrieve.
If the unnamed value does exist, you can retrieve its value:
- Using the Get-ItemPropertyValue PowerShell cmdlet:
  - Refer to it by literal string '(Default)' (irrespective of what the Windows display language is) as the -Name argument.
```
# NOTE: FAILS, if the unnamed value doesn't exist.
Get-ItemPropertyValue -Path 'HKCU:\AppEvents' -Name '(Default)'
```
  - As an aside: Due to a bug, still present as of PowerShell (Core) 7 v7.4.x, Remove-ItemProperty does not recognize '(Default)' - see GitHub issue #6243.
- Alternatively, using the .NET .GetValue() method of the [Microsoft.Win32.RegistryKey] type, in combination with Get-Item, which outputs such instances (when targeting the registry).:
  - Use '', i.e. the empty string:
```
# NOTE: Returns $null, if the unnamed value doesn't exist.
(Get-Item -Path 'HKCU:\AppEvents').GetValue('')
```
  - If the unnamed value exists, it is also returned as a '' element from the .GetValueNames() method.

If you want to quietly default to $null if the unnamed value doesn't exist:

# Using Get-ItemPropertyValue.
# NOTE: Also ignores the nonexistence of the *key*.
$unnamedValueDataIfAny =
  try { Get-ItemPropertyValue -Path 'HKCU:\AppEvents' '(Default)' -ErrorAction Stop } 
  catch { $null }

# Using .NET.
# NOTE: Reports an *error* in the event of nonexistence of the *key*.
$unnamedValueDataIfAny =
  (Get-Item -Path 'HKCU:\AppEvents').GetValue('')