Declare Function GetUserName Lib "advapi32.dll" Alias "GetUserNameA" (ByVal lpBuffer As String, nSize As Long) As Long
Public Sub Main()
Dim sUser As String
Dim lpBuff As String * 1024
'Get the Login User Name
GetUserName lpBuff, Len(lpBuff)
sUser = Left$(lpBuff, (InStr(1, lpBuff, vbNullChar)) - 1)
MsgBox "Login User: " & sUser
End Sub