Hi, three years ago I helped my mom get a G3 iMac 500mhz with dinky 20gb hd. Upgraded her to 768mb memory but now with 10.3.7, she's getting the spinning beachball a lot. I'd like to upgrade her to 1 gig and a new harddrive but don't know if her machine can take a 160 gig 7200rpm Hitachi deskstar? Would her machine only recognize 120 gigs? I seem to recall this limitation -- anyone know about this? Also, because this is an academic iMac, she has cd rom only! What kind of cd/dvd player could I get for this slot loading machine?