Of course, as mentioned before you can always talk to KUKA. Usually they are eager to help in cases like yours and provide the software. Most of the time even free of charge if they find in their databases the software was already licensed for your robot. Otherwise you are not allowed to install any software anyway may it come from whatever dubious source.
As already mentioned before usually the installers and deinstallers are on drive d, so check there on what you can find.