No. Final Draft 12 will install to its own folder and won't overwrite any earlier version. You can uninstall any older versions of Final Draft if you don't plan on using them, and it's best to uninstall them before installing the newer version. On Windows, if you uninstall an older version of FD after installing FD12, the Courier Final Draft font may get uninstalled. If this happens, uninstall and reinstall FD12. This will ensure that the right font is in place.