Hello chahira,
Welcome to the PhotoDirector forum
After setting up your slideshow, what steps did you take? e.g. Did you go to Produce or Share? What video format & profile did you select? Output folder? What audio was used?
Though I don't usually upload slideshows through PhD (only WMV available), I've just done so without a hitch. Producing the video in different formats presented no errors either, in both Win 8.1 & Win 7. So, it's not an inherent problem with the software or OS.
The more information you can offer, the easier it is to track down the issue.
PIX
PIX YouTube channel