$Namespace = "ReadRegDate"
Add-Type @"
using System;
using System.Text;
using System.Runtime.InteropServices;
$($Namespace | ForEach-Object {
"namespace $_ {"
})
public class advapi32 {
[DllImport("advapi32.dll", CharSet = CharSet.Auto)]
public static extern Int32 RegQueryInfoKey(
Microsoft.Win32.SafeHandles.SafeRegistryHandle hKey,
StringBuilder lpClass,
[In, Out] ref UInt32 lpcbClass,
UInt32 lpReserved,
out UInt32 lpcSubKeys,
out UInt32 lpcbMaxSubKeyLen,
out UInt32 lpcbMaxClassLen,
out UInt32 lpcValues,
out UInt32 lpcbMaxValueNameLen,
out UInt32 lpcbMaxValueLen,
out UInt32 lpcbSecurityDescriptor,
out System.Runtime.InteropServices.ComTypes.FILETIME lpftLastWriteTime
);
}
$($Namespace | ForEach-Object {
"}"
})
"@
# Store the type in a variable:
$RegTools = ("{0}.advapi32" -f ($Namespace -join ".")) -as [type]
# Get a RegistryKey object (we need the handle)
$RegKey = Get-Item HKLM:\SOFTWARE
# Create any properties that we want returned:
$LastWrite = New-Object System.Runtime.InteropServices.ComTypes.FILETIME
# Call function:
$RegTools::RegQueryInfoKey($RegKey.Handle, $null, [ref] $null, $null, [ref] $null, [ref] $null, [ref] $null, [ref] $null, [ref] $null, [ref] $null, [ref] $null, [ref] $LastWrite)
# Convert to DateTime object:
$UnsignedLow = [System.BitConverter]::ToUInt32([System.BitConverter]::GetBytes($LastWrite.dwLowDateTime), 0)
$UnsignedHigh = [System.BitConverter]::ToUInt32([System.BitConverter]::GetBytes($LastWrite.dwHighDateTime), 0)
# Shift high part so it is most significant 32 bits, then copy low part into 64-bit int:
$FileTimeInt64 = ([Int64] $UnsignedHigh -shl 32) -bor $UnsignedLow
# Create datetime object
[datetime]::FromFileTime($FileTimeInt64)
Notes
also see Notes in: C# – Return LastWriteTime Registry Key