HotFix 6.20 Installation errors

I am getting an error trying to do the new update that says "Failed to continue. Cannot reinstall in this directory. Another version of same media is already installed here". I got this error on the 6.13 patch and figured when the next patch came out it would over right everything. But this is two patches in a row i can not install and there are no directions as to which files need to be deleted in order to continue with the update. If anyone can offer help it would be greatly appreciated. Thanks, Greg

Installation Error Edu ​​​​​​​HotFix Error CATIA​​​​​​​​​​​​​​