Quote - was pretty smart by installing P7 on a PC and then copying and pasting the runtime folder onto my external F drive. It worked ! ,until I tried unzipping and installing stuff to it.

What sort of problems did you have unzipping to external runtimes? It's one of the easiest things to do if the zip is properly archived with the paths intact. External runtimes also saves you from repeatedly having to redo your runtimes each and every time you upgrade to the newest version!