Registration loop

Hello,

I installed a new hard drive. Installed win xp home. system boots to user screen. click on owner. screen changes to "need to register win xp" I click OK. comes up win already registered, click OK to exit. when I click OK it goes back to user screen. Click on owner, and again says I need to register. I tryed saying "later" but that just sends me back to the user screen. Loop! can anyone help? please! thanks so much!