You have to have the Ultimate version of Windows to do this. It is possible to enable DreamScapes with non-Ultimate versions, however this is not the forum for that.
Unless your computer is capable of handling the power required by this, it's pretty much useless, however it is nice to have some movement while doing mundane tasks in Windows (i.e. listening to music, etc...).
Long videos become rather annoying btw! Simple and subtle are the way to go.