I was recently given a g4 from my school. I am trying to install a program that was compressed and carries an .sit extension. I tried installing betterZip, Stuffit, etc. For some reason, after installing, the applicaitons will not open. I dragged them to the app. folder, which sort of seemed pointless, and tried again. I restarted the computer and to no avail. The icons are there, but nothing happens when I click on them. I am so confused...and frustrated! Could there be some sort of administration option that prevents me from installing new software, even though I am logged on as the administrator? If so, how do I unlock it? I am new to Macintosh, so forgive my ignorance. Could someone please help me?