It is an ISO image file within a RAR file so you will have to extract the ISO image inside it so it can then be to burnt to CD & then installed on your PC.
As Peter has said you will need WinRar (free off the net) to extract the ISO file from inside the Rar file. Then you need Nero or Magic ISO or similar CD/DVD burning software to then burn the ISO image (as an image) to a CD. The program can then be installed on your computer from the CD & it (the CD) has to be in the drive while using the program but as Peter has said it is an old Format & doesn't like the newer browsers.
Note: although it says 94-02 it does not cover those models it covers the 00,02-06 2.0 Petrol 2.0,2.3 & 2.8 JTD models the same as the newer eLearn version but uses the old DTE format. The elearn version is more comprehensive & much easier to use & it is also in a RAR file as above.
Which particular model Ducato do you want the info on as it doesn't cover the 1.9 2.5, 2.8 2.8TD or 2.8TDi 230 Ducato models although some of the other sections - body, brakes, suspension etc might be applicable ?
Hope this helps
Cheers