Core 2 Duo (Dual Core Settings)

[Nechen]

Are there any specific settings I have to modify within windows to take advantage of Dual Core? The only thing I've seen is "Set Affinity" in Task Manager wherein I can say which CPUs they can/cannot use. If I set all my Background apps to only run on the Second CPU does that mean that my First CPU will be dedicated purely to Games when I run them? Or does it really not matter?

Thanks!