OriGin on 30 June 2007
Pentium 4's were awesome for overclocking, you should be able to put the clock speed of that up to probably 3.5 - 3.6 Ghz if not more... the 4's scaled really well.
Thats not to say that you should bump it straight up to a really high number though, it takes a long time and you need to do it in small increments.
The problem with your PC is the 480MB of ram... that seems exceedingly low... u sure it's only 480?
