Windows XP activation problems

Is anyone else having activation problems with WinXP? I have 3 different PCs, all with legit product keys, and none will activate. When I try on line activation, I get a message I've never seen when trying to activate; one PC said this:
Windows was unable to activate online.
The activation period has expired. You must activate your computer now to continue using Windows.
You can activate by telephone... blah... blah...

It refuses to activate on line; when I call via telephone, I'm told the product ID is not valid and cannot be verified even though I'm staring at the product key sticker on the side of the PC. I can't remember what the message for the other 2 PCs was, but I know it was along the lines of "the product ID is not valid and could not be activated online." and when I call, I get the same thing about the ID not being valid and could not be verified. So, what's up with this? Is the validation/activation server down or something? All the PCs I'm trying to activate are totally legal and have legit product key stickers, and all have been activated about 8 months ago without issues. I'm doing "spring cleaning" and formatting/reloading these PCs to get 'em all in "day one" condition. Any ideas? Comments? Help!??!?!

 

Do they have FF 3.0 on them?

http://forums.microsoft.com/Genuine/ShowPost.aspx?PostID=3541871&SiteID=25

 

also you might try this...http://www.microsoft.com/genuine/diag/

 

Thanks, but the problem has been solved. I eventually got to speak with a human over at Microsoft Licensing (in India or Pakistan) and was told that because these were "old OEM product keys that hadn't been activated for a long time" I was "required" to go the extra mile and do it via human and that none of the automated option would work the next time I tried to activate these same keys. Strange? Yes. Surprised? No. None of Microsoft's stunts surprise me anymore, especially when it comes to licensing issues....