The Install sub-menu creates shortcut icons and file associations. This sub-menu is not present if you use PgcEdit.tcl with an external Tcl/Tk interpreter, or under Linux or Mac. If you wish to open PgcEdit directly by double clicking a file type, it is wise to associate BUPs with PgcEdit. Other programs (such as your software player) may like to have IFOs to themselves.
It’s also a good idea to associate Scratchbook (“sbk”) files with PgcEdit.
You may also install a plugin via this menu. PgcEdit will open your plugins sub-folder and you can extract the plugin from a zip file to that folder. You should then close and re-open PgcEdit.