First step: Select the drive you want your new Runtimes to be on. (External drive or what not). Then create the files that your content will be sent to example:

 

Poser 7 Runtime

-         Victoria 3

-         Victoria 4

-         Aiko

-         Hair

-         Props

-         Lights

-         Ect

 

1: If the Poser palette is hidden, click the bar at the right side of the interface to expand it.
2: If the Library Palette opens to display the library titles and not their contents, double-click any library category name (Figures, Cameras, and so on) to display the contents within it.
3: The first folder in the library is usually a special folder, the “up folder.” The arrow on the folder is an indication for you to click on this special to move up to the next highest folder level. To move to the very top, or root, of your currently selected library folder continue click the “up folder” until you see a red dot next to the folder icon. The red dot indicates your currently active Runtime folder, and it also tells you that you are at the top of your library structure, or the root. You can add new Runtime libraries while you are in a root folder.

4: Now that you are in the top-level folder, two icons should appear at the bottom of the Library Palette window: a check mark and a plus sign. When you hover your mouse over the plus icon you see the words “Add Runtime.” Click the plus-sign icon to open the Browse for folders dialog box.     

 

Info Taken from the Practical Poser 7 Book.  Hope it helps