Can't access install new media page on the website.

Hi! I am attempting to insert videos into an e book I am writing, I am using Serif Page Plus 8 and Acrobat reader. The video symbol appears on the PDF  but when I show the page in Acrobat Reader and click the symbol  I get an error message telling me I need to download a further media player. When I attempt to download the player The web site brings up a message, Forbidden: no browsing in this folder. Can anyone advise, please?