what I can say, is ask your father if you can install the game with the default settings, and hide the CD from the rest of your siblings

(you can't play without the CD anyway)
and maybe it's time for a spring cleaning on the computer. if 7-8 people are using it, the space on the hard drive is used pretty quick.
then, it may be room for a game like sims2. it's a game that takes up a lot of space, and is not the best game for slow computers. I myself have all sims2 EP's (and most of the SP's) installed, and even without CC, my game is a bit slow. add a couple of gigs to the DL folder, and only startup takes half an hour...
< *needs new, faster computer - with more memory, space and better graphics*