I'll try to translate it to English, tough it will probably not be grammatically right or something.

Here is the error message I got when trying it with Autorun clicking on Play, JCS or UnInstall.

Translated into English (might not be correct):

"While trying to start Jazz Jackrabbit 2 an error has occured.
Error: The system can't find the path."

If I open the CD manually without Auto-Run I get this message (again might not be correct translated):

"This program installs Jazz Jackrabbit 2 Version 1.20.
A newer version of Jazz Jackrabbit 2 has already been installed on your computer. You can replace it with Jazz Jackrabbit 2 Version 1.20.
Installation will now be ended."

Again, sorry if I translated wrong, but I think it would be something like this in English.