hi for lha packages you have to get lha.run copy that to c drawer then open shell go to c: then type lha.run after extraction is succesfull reboot.
to open lha extensions open shell go to drawer where lha file is and type lha x name.lha then enter and it should extract in that drawer close shell and open the drawer and it should be there.
you may have to update the drawer to see it but not always cheers.
