You need to use relative references to your files! This is the same for both Word and Excel.

First you need to understand the difference between 'absolute' references and 'relative' references...

If you think about them like references to Cells in Excel:
An ABSOLUTE reference points to an exact cell, and it never moves ($A$1)
A RELATIVE reference points to a cell, but if the formula is dragged around the page, the reference can change (A1 - dragged to the right becomes B1)

This is the same idea with hyperlinks in Documents and Spreadsheets.

What you need to do is:

• Create a folder where you are going to store the document
• Inside this folder, create another 'Store' folder - this is where you are going to point your links, and where you must ALWAYS keep the linked files! - if you move the documents, you MUST ALWAYS move the entire document folder WITH the Store folder inside it!
• Place your linked files inside the folder
• To create the Hyperlink, simply do the process as before, but then edit the created link and REMOVE all of the path from before the Store folder.

eg: your original Hyperlink is:
C:/My Documents/My Link Files/My Linked Files/audio.mp3

Your finished hyperlink is:
../My Linked Files/audio.mp3

You need to include the '../' at the beginning, as it is needed to indicate that it is a relative path.