I got my computer August of 2006 it’s an HP special Edition. I have norton Antivirus installed and I put most of my big files on an external hardrive. Recently, it has slowed down drastically (ex: Taking forever to turn off or on, to open or close widows, to switch to different windows and to download webpages, open itunes, etc.) How do I fix the problem?

plz help!!!!!!!?

ok, my computer will not load anything, no sound, no drives, nothing but the desktop. it will open widows and software. norton auto protect was shut off not by me, and it wont turn back on. the internet wont load, my widows restore points were erased. it is not on diagnostic mode, for i have checked that a million times. what could be the problem? i admit i was on a site i shouldn’t have been on, and some how i contracted a trojan. but this trojan i removed manually in diagnostic mode. how can i fix it?????
and i tryed rebooting 3 times
MY INTERNET DOESNT WORK. IU CANT DOWNLOAD ANYTHING.

My system registry was cleaned using CCleaner.(This program is a freeware and downloaded from http://www.ccleaner.com/)

In this process I lost all updates(something around 100 updates..) of windowsXP SP2,which is a pirated version.The updates are periodically down loaded from windows website

And I couldnot undo the action.

But my system is working normal even after loosing the updates listed in control panel>add remove program window.

My doubt is why CCleaner programs recommonded to remove the updates when they are part of widows XP operating program.

And what could be the consequenses I have to face because of the loss of updates in the future.