Is windows sp2 really needed cuz i reinstalled my xp copy with sp1 and my computer seems faster?

No it's not needed, but it does make certain aspects of your computer safer if you're not familiar with all the in's and out's.

Is windows sp2 really needed cuz i reinstalled my xp copy with sp1 and my computer seems faster?internet browser

Well, you're right, Windows XP SP2 does slow down, older... and... I do mean OLDER systems. That's not a problem for someone like me who is on top of the latest and greatest. But, I would suggest that everyone installs SP2. It's more of a memory problem than anything else. I'd say have no less than 256MB of memory if you want to have SP2, 512MB highly recommended, 1GB is even better... but why not have 2GB of PC3200 memory (which is what I have in my desktop).

Is windows sp2 really needed cuz i reinstalled my xp copy with sp1 and my computer seems faster?windows media center internet explorer

It is absolutely necessary at this point in time if you are connecting that computer to the internet. The number of exploits that are available (and now fairly well documented) to even novice "hacks" makes it needed.