Hi Jim, I use AutDebug.exe only with AutoIt v2. Create an AutDebug.exe shortcut. Drag and drop the script generated (.aut) until this shortcut. Two windows appears on the screen. The right window shows script variables and executing lines. The left window shows seven buttons. I normally use the step button. Every time I click this button I see in the right window the new changes. Sometimes is necessary to click this button several times for executing a line. The buttons Faster /Slowler sometimes not work. But be patient!. AutDebug is very slow if your script have a lot of code ! I hope this explanation helps you. (Better you ask Larry, the author, about AutDebug.exe). For this issue, can you show what do you do with xxcopy ? Some line code... etc.