guys whts the diference bw sp2 and 3? and which one is better?

Definitely SP3 is better.

The Service Packs are just collection of all updates and patches released by Microsoft for their OS. Here SP3 contains more patches and updates than SP3. In other words, SP3 is most recent version of their patches and Updates.

Also, as per user reviews and experience, its noticed that after installing SP3, windows XP was little quicker and better in use as compared to SP2.

Service Pack 3 is basically just a bunch of previous updates Microsoft has released since SP2 rolled into 1 big download. It's other features are for applications that Vista uses with newer server platforms. For the basic user, there are no new features or improvements...i dont know whether the previous one has updated, but i sp3 has few problem...