Get-RegistryValue.ps1

function Get-RegistryValue
{
    [CmdletBinding(DefaultParameterSetName = 'HKLM')]
    param
    (
        [Parameter(Mandatory = $true, ValueFromPipeline = $true)]
        [string[]]
        $Key,

        [Parameter()]
        [string]
        $ValueName,

        [Parameter(Mandatory = $true, ParameterSetName = 'HKU')]
        [string]
        $SecurityIdentifier
    )

    process
    {
        foreach($k in $Key)
        {
            if((Get-WmiObject -Class Win32_ComputerSystem).SystemType -match 'x64')
            {
                $RegView = [Microsoft.Win32.RegistryView]::Registry64
            }
            else
            {
                $RegView = [Microsoft.Win32.RegistryView]::Registry32
            }

            if($PSCmdlet.ParameterSetName -eq 'HKLM')
            {
                $basekey = [Microsoft.Win32.RegistryKey]::OpenBaseKey([Microsoft.Win32.RegistryHive]::LocalMachine, $RegView)
                $keyname = $k
                $subKey = $basekey.OpenSubKey($k)
            }
            else
            {
                $basekey = [Microsoft.Win32.RegistryKey]::OpenBaseKey([Microsoft.Win32.RegistryHive]::Users, $RegView)
                $keyname = "$($SecurityIdentifier)\$($k)"
                $subKey = $basekey.OpenSubKey("$($SecurityIdentifier)\$($k)")
            }
            
            if($subKey)
            {
                foreach($value in ($subKey.GetValueNames()))
                {
                    if($PSBoundParameters.ContainsKey('ValueName'))
                    {
                        if($value -eq $ValueName)
                        {
                            $props = @{
                                Key = "$($PSCmdlet.ParameterSetName)\$($keyname)"
                                ValueName = $value
                                Value = ($subKey.GetValue($value, $NULL, [Microsoft.Win32.RegistryValueOptions]::DoNotExpandEnvironmentNames))
                            }

                            New-Object -TypeName psobject -Property $props
                        }
                    }
                    else
                    {
                        $props = @{
                            Key = "$($PSCmdlet.ParameterSetName)\$($keyname)"
                            ValueName = $value
                            Value = ($subKey.GetValue($value, $NULL, [Microsoft.Win32.RegistryValueOptions]::DoNotExpandEnvironmentNames))
                        }

                        New-Object -TypeName psobject -Property $props
                    }
                }
            }

            $basekey.Close()
        }
    }
}