Verify the Windows Password

Add a new bas module (modVerifyPassword) and copy the following code into it:

Option Explicit

Declare Function GetUserName Lib "advapi32.dll" Alias _
  "GetUserNameA" (ByVal lpBuffer As String, _
  nSize As Long) As Long

Private Declare Function WNetVerifyPassword _
    Lib "mpr.dll" Alias _
    "WNetVerifyPasswordA" _
    (ByVal lpszPassword As String, _
    ByRef pfMatch As Long) As Long

Public Function GetWindowsLoginUserID() As String
Dim rtn As Long
Dim sBuffer As String
Dim lSize As Long

sBuffer = String$(260, Chr$(0))
lSize = Len(sBuffer)
rtn = GetUserName(sBuffer, lSize)
If rtn Then
  sBuffer = left$(sBuffer, lSize)

  'Reformat string
  If InStr(sBuffer, Chr$(0)) Then
    sBuffer = left$(sBuffer, InStr(sBuffer, Chr$(0)) - 1)
  End If

  GetWindowsLoginUserID = sBuffer
Else
  'Error!
  GetWindowsLoginUserID = ""
End If
 
End Function

Public Function VerifyWindowsLoginUserPassword _
  (ByVal Password As String) As Boolean
Dim rtn As Long, Match As Long
rtn = WNetVerifyPassword(Password, Match)
If rtn Then
  VerifyWindowsLoginUserPassword = False
Else
  VerifyWindowsLoginUserPassword = (Match <> 0)
End If
End Function

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This article was originally published on November 20, 2002