I have downloaded the Eset Nod32 Antivirus from its website, and I got a eset_nod32av_64bit_en.linux file. I have right-clicked on it, Properties - Permissions, and checked the Allow executing file as program option. Then I was able to run the program. The Installer starts and it asks for my root password. I enter it correctly, but then I get the following error message: "su: Authentication failure". What can I do with this to install the Nod32? Thanks!