Could I get help as trying to download Windows XP service pack 2o replace service pack 1 but it gets so far and then I get the message access denied. I done what Microsoft support states to do but I can not find the registry key that I need to enable

Can you post a link to the Microsoft Article or support document that you're referring to? If we know what registry setting you're talking about, maybe we can help you find it.

Microsoft is really nice and they offer to send you a cd that contains service pack 2 on it (for free) so you dont have to sit and wait for the download. Here is the link
Its also a nice tool to have if you reinstall windows from scratch a lot.

However, i think it is saying that it can not verify that you have a valid windows xp install. Correct? If this is the case, just go in internet explorer to the tools menu-> internet options-> advanced tab-> and click the button that says restore to defaults. That should do the trick.

Hope this helps :)