installing sp3 in office xp standard

[Jo]

I have windows xp standard as well as office. I need to install the service
pack becuase its not letting me respond to email i get from my website.

I have dowloaded the update but I can't install it. It's telling me I have
to use my cd, which i put in but I cant find the right file.

So I went back online and used the download for when you dont have your cd
and it STILL asks for the cd.

Cany anyone help me with this, I feel like I'm going in circles.