That dialog box 'MACRO: Open macro' is what AutoIt is opening from TeraTERM's Control->macro command. I don't have access to a XP machine at work or home, so afraid I can't comment on why AutoIt is not able to automatically fill out that dialog box as it should. But, you have the source code so feel free to play with it (try about line 775 or so) and let me know if you find something that works and I will backport it. It is possible that the latest version of Autoit is not even supported on XP, in which case ButtonBar would have to be modified to work on an earlier version of AutoIt that supports XP, something that I personally am not really interested in doing, sorry. You might try updating TeraTERM to the latest version, too.