Probably a very bad idea to drag and drop the entire Runtime into the P5 folder as you will end up over-writing a whole lot of newer and updated files (eg. don't expect Python to work after you have done this, probably a lot more to boot). Beyond this, at least in some previous P5 versions, there were problems with installing new content in the P5 library directories and, for that reason many people keep their P5 library structure pretty virgin and still use their P4 directories, or a seperate Runtime directory for installing new content. As Wadus says, you can istall P5 in a seperate directory and then use P5's library linking functionality to access the P4 Runtime (or others) directly. It also means that you can continue to install new content in the P4 directory and have it available to both versions without having to install it twice. The only thing you probably need to re-install in the P5 Runtime is V3 since the morph injection process takes considerably longer if the injection files are not stored directly in P5's native Runtime. Bill