This option in installer controls location of your User Data directory.
All settings, syntax files, workspaces etc can be installed (and later loaded) from three different locations:
Default for new users is Current Application Data.
For existing users old location (for most it portable mode). Once selected, the mode cannot be changed. To install to a new location, you need to do full uninstall first.
If checked, add a path to hippoedit.exe to PATH environment variable, so you can call it from command line from everywhere later.
On Uninstall, PATH state is restored and HippoEDIT directory is removed.