I thought I would bump this with an update. This issue still remains unresolved. I did get a reply from NI Support with this message: "This is for Win7. Go to C: folder Open Organize>Folder and search options Then go to View tab and turn on Show hidden files, folders, or drives Then go to ProgramData and right click PackageCache and open Properties Go to Security tab and edit Permissions to allow Full control" I followed the instructions and after a reboot tried another install of Kontakt 5.4.1 again without success. So I remain unable to update any of NI products because of this. I replied back to Support but as yet, have received no further help. If anyone can provide any suggestions I would be most grateful. Thanks.