See Where a Hyperlink Will Really Take You
The Problem:
I've been sent a document with a hyperlink in it, but when I click the hyperlink, my browser displays a page with a different address than the one in the hyperlink.
The Solution:
You might find this annoying, but it's not a glitch. The anchor text for a hyperlinkthe text that appears in the document to indicate the presence of the hyperlinkdoesn't have to be related to the URL used in the hyperlink. Thus, you can create a hyperlink with descriptive text (for example, "Click here to display the brochure") rather than the address of the hyperlink.
Where this gets confusing is when, for example, someone pastes a URL or email address into a Word document. Word automatically creates the appropriate type of hyperlink (for example, an http:// hyperlink for a URL and a mailto: hyperlink for an email address) and displays the pasted text as the anchor text. If someone then accidentally (or intentionally) edits the anchor text, it will be different from the target URL or email address to which it is linked, but the link will still be correct, as long as it was correct in the first place.
If you need to edit the target address of a hyperlink, or you just want to see where it will take you, right-click it and choose Edit Hyperlink. (In Word 2000, right-click and choose Hyperlink 
Edit Hyperlink.) From the Edit Hyperlink dialog box, you can edit the text of the hyperlink and the URL to which it links.