Windows xp genuine serial keys:

Here are Genuine keys for Windows XP:

Also check:How to Make windows xp fully Genuine?

For SP2(Service Pack 2):

Windows XP Service Pack 2 (SP2) Genuine Serial Key
                  DYKRH-48DMG-PHKGY-4329Q-PXGHT

For SP3(Service Pack 3:

 Windows XP Service Pack 3 (sp3) Genuine Serial Key
                  MR49R-DRJXX-M6PX2-V96BF-8CKBJ