I have an old but good IBM PC which I am happy with. I think it has a celleron 300, has 64MB RAM, and a 4Gig HD. Would it be worthwile to upgrade the HD to something bigger and add some RAM or should I just start from scratch on a new PC(buy or build)? I am looking for more room to store MP3's and a little more performance for games. I think the model is 300GL or something like that. It's a small tower computer.