The reason they were not supported is because there are some security concerns with local files (especially local image files). On some systems, simply reading an arbitrary file can cause problems. (For example, one might read a file attached to a very slow device (like a tape drive).) To be safe, the 0.92 release did not allow local file links.
In UseModWiki 1.0 there is a new option $LimitFileUrl? (1 by default). If it is set to 0, then "file:" links will not be restricted. This setting is not recommended for public wikis, but it may be useful for private ones. --CliffordAdams
Question Is it possible to format a local file link that contains spaces (on a Windows system)?
Space is used as a separator to determine the end of an URL. Replacing the spaces with %20 should work. -- MarkusLude
Still no luck, I have tried the following links but neither work, the second link gets the trailing backslash striped, which I believe IE needs (if I click the link I get a 404, but if I add an extra / it works)