Protect Word document to prevent Copy

This [trick] is what's known as "a fool's errand".

You can click Tools > Protect Document, in the task pane click the
check box under "Editing restrictions", set the dropdown to "Filling
in forms", and click the Start Enforcing Protection button. If your
document doesn't contain any form fields, it will behave as you
described -- clicking anywhere in the document will send the cursor
back to the top of the document.

However, this "protection" is so easy to defeat that it's laughable.
Just open a new blank document and use the Insert > File command to
insert the protected document. Presto, no protection.

Even if you manage to come up with a better protection scheme, such as
using Microsoft's Information Rights Management (IRM), it's still true
that if someone can see your document they can reproduce it in
editable form. The best you can do is to make it more difficult for
them.

Source:
http://help.lockergnome.com/office/Prevent-Copy-Clipboard-MS-Word--ftopict1000189.html