This computer was purchased only a few days ago and I am trying to limit CPU usage as much as possible. I am used to and like the minimal XP consumption

So, upon getting to know the computer I saw that even while idling the CPU consumption was around 64%--which I figured would not allow me to do videos etc.--so I set out to decrease based on what little I knew, and I am still in need of help with determining what I don't need and how to decrease it further.
I uninstalled Windows Live Essentials, installed the Vista version of Media Player, turned off all but the IE in Windows Features, disabled many start up actions (not sure if I need to do more, or even enable certain ones again), and I increased the paging files substantially for both drives. This really, really helped lower the percentage of energy used by both cores, and general CPU usage, but the RAM's still at 2475 of 3691 when no windows/browser is open. I'd like to decrease that.
I have not yet set out to disable anything while the machine's running, just upon start up.
Any help would be greatly appreciated.
