how do I change the format of my workspace it is limited to vertical only?
What do you mean by a vertical workspace?
Is it the way that the panels are laid out, or by workspace, do you mean the video frame?
Either way, please post a screen shot so we can see what you mean.
You really need to be more specific and use terminology from the program. There is no panel called the "edit window." And I can't begin to guess what you mean by "the complete window needed for full video screen." As Steven suggested, a screenshot could really help.
If you're basically asking how to rearrange the layout of the panels, you can do that by mousing over the divider between any two panels and then clicking and dragging side-to-side or up-and-down.
See the Workspaces sections of this help document: http://helpx.adobe.com/pdf/premiere_pro_reference.pdf