I got 99% of my runtimes on an external drive. The content that comes with the install of the program is installed to the main runtime in my Public Documents folder on my hard drive, Python scripts to Program Files/whatever Poser iteration is the latest/Python/poserscripts...everything else is manually placed into the external runtimes via Windows Explorer. That way, I am completely in control and although during a brand new install I have to manually re-add my runtimes via the little + sign in the Library window, I know exactly what I add. (and I've learned this by reading the manual and readmes of products I purchase. My money, my responsibility not to break it).