This works for me (uncomment one or the other of the following methodĀ  so they do not interfere): #include <Word.au3> Global $oErrorHandler = ObjEvent("AutoIt.Error", "_ErrFunc") Global $oWord = _Word_Create() Global $oDoc = _Word_DocOpen($oWord, @ScriptDir & "\test.docx") Global $oRange1 = _Word_DocFind($oDoc, "TestRange1") $oRange1.Underline = True MsgBox(0, "", "Range1 found and underlined") Global $oRange2 = _Word_DocFin