Background worker and progress bars tutorial

I have recently knocked up a simple tutorial of the use of background worker and progress bars when there's a need of use such. General purpose is to make a more user friendly interface, as sometimes the program will hang if the processing time takes more than a few sec. ( some users will then think the program is dead and may force shut down the program.)
ppt link:
https://sites.google.com/site/maimailearns2vb/first/Back%20Ground%20Worker%20n%20Progress%20Bars.pptx?attredirects=0&d=1