1. To select your hidden slides, from within the slide sorter view go to the pptXTREME menu and select moreEdit > Hide/Unhide > Select hidden slides

2. pptXTREME Select Hidden Slides will select ALL hidden slides, pptXTREME Hidden Slides and Standard PowerPoint Hidden slides

(HINT: Hold down the <shift> key to choose which hidden slides you would like to select, All Hidden Slides (pptXTREME and Standard PowerPoint Hidden slides, Only pptXTREME Hidden Slides or Only Normal PowerPoint Hidden Slides.)