aggiungi un modulo
codice:
Public Declare Function GetUserName Lib "advapi32.dll" Alias "GetUserNameA" (ByVal lpBuffer As String, nSize As Long) As Long

Function TrovaNome() As String
Dim sName As String
Dim lName As Long
   lName = 255
   sName = Space$(lName)
   If GetUserName(sName, lName) <> 0 Then
      TrovaNome = Left$(sName, lName)
   End If
End Function