I don't know how it works the first time. You are blocking the UI thread by looping till the worker thread completes. So your calls to PerformStep won't really get through till button_Click completes, by which time you're already done. I'd suggest that you update the progress bar from the worker thread (by using BeginInvoke/Invoke as this[^] article describes. Regards Senthil _____________________________ My Blog | My Articles | WinMacro

yeah that crossed my mind too. but it seems a bit sadistic to me anyways. funny thing is i knew about Application.DoEvents() and actualy used it .. but to no result. in my test i placed it in the while loop because normaly you want from time to time the app to respond to other calls but oddly it didn't work(no idea why thow). the other thing that crossed my mind was to add a messageFilter before thread.Start and remove it after my task finished. but that's a bit too costly in my opinion.