Micro$oft finally figured out with XP that when a person copies files from a CD to their computer that they, most likely, want them to be read/write. So, if you're using XP, this shouldn't be a problem.
Other than that, what Mark says is true.
The only other thing to check: For some reason, with some versions of R14 (yes, there are different versions) AutoCAD sees every file in a folder that has a 'dot' ( . ) in it as 'read-only'.
In other words, if you put the drawings in a folder named
C: \2003.drawings
AutoCAD R14 will assume that they are 'read-only'. Get rid of the 'dot' and all will be well.