Private Declare Function GetUserName Lib "advapi32.dll" Alias "GetUserNameA" (ByVal lpBuffer As String, nSize As Long) As Long
Private Sub Form_Load()
    Dim strUserName As String
    strUserName = String(100, Chr$(0))
    GetUserName strUserName, 100
    strUserName = Left$(strUserName, InStr(strUserName, Chr$(0)) - 1)
    'Show the temppath and the username
    MsgBox strUserName
End Sub