I have been trying to do this for last 3 days but nothing seems to be working (correctly). What i am trying to do is extracting an iso image to my pendrive during which progress bar should show the process. The actual size of the archive size is not known but no significant difference is there after extraction. Here is my code and where am i making mistke? #include <GUIConstants.au3> #include <GUIConstantsEx.au3> _PROGRESS () Func _PROGRESS () $Progress = GUICtrlCreateProgress(8, 5