kyhwana2 just gave the real answer, for regular home/office use a laptop with core i3 would be good enough, however those pre-build OS always came with heaps of junks, running recovery CD or use hard disk recovery would be helpful, suggest you do a fresh installation if you can, that will make things much better.

Yeh I did a fresh install and it works ok now, but i've only installed Chrome, the new Windows live messenger, skype, and iTunes. I want to put a retail copy of Win7 on it but HP told me that voids the warranty for some stupid reason. 

To be honest, no offensive, HP help desk are totally useless, and I'm sure changing the OS WON'T void the warranty, I've got many laptops and I've never used the factory pre-build OS, and I've done many times warranty claim/repair with different brands, and service centres, basically they won't even bother with the OS as it is just software!