Microsoft introduced some innovative packaging for Windows Vista and Office 2007 installer DVDs. They ship inside a hard, plastic container that's also shrink wrapped.
What Microsoft forgot to provide you is a separate manual or instructional video that would demonstrate how to open these Vista or Office 2007 boxes.
An Office 2007 customer had a real hard time opening the DVD casing and he therefore posted a step-by-step picture guide on Flickr illustrating how to open the Office 2007 box. The process should be similar for Windows Vista.
His advice - use a pocket knife or pair of scissors to slice the transparent, circle-shaped top seal along the edges and then lift the red Post-It flag at the top left corner of the box.
Detailed Tutorial available on Flickr.com. Microsoft designed these software boxes to last a lifetime, this photo essay should help you open the box without scratching the case.
This tutorial also shows how Flickr (or any photo sharing website) can be used for writing tutorials on the lines of Instructables.