I used the update option in Microsoft Security essentials and it updated smoothly
also i upgraded MSE using the upgrade button on the main home tab
does that mean my windows is genuine?
system info:
System:
Microsoft Windows XP
Professional
Version 2002
Service Pack 2
Pls help I need to update my XP to SP3

Your Windows is “Genuine” if you have a legitimate license from microsoft for the OS. In other words, you didn’t pirate it.
If you have the sticker somewhere on your machine that says microsoft windows genuine and has a long serial code, then it’s likely genuine.
It will check you system to see if your Code is legitimate or not when you go to install SP3. You should be able to do so via Windows Update.
The website Microsoft.com can predict that your win is genuine or not.