Windows XP Activation Loop

My computer was messing up so I formatted it.  No big deal.  Go through the normal install stuff and before it lets me login it says I have to Activate.  Weird, but ok.  It says do it online or over the phone.  I try online.  It says it can't find a connection.  I go to try to do it on the phone but the is no key to read to the phone service.  So I Google it and find that it needs a netcard to be installed in order to produce a key to call it in.  So I install a card in Safe Mode, since I can't get pass the Activation.  I reboot and a key has appeared.  I call and do the whole thing it is now activated.  So I click to login and it says I have to Activate.  I try online and it says you are already Activated.  So I'm stuck.  

It turns out that I was installing with a Windows XP SP2 disk but putting in a SP3 key.  Once I reinstalled with a SP3 disk everything went fine.