In order to install LogMeIn Backup manually or upgrade the version from an older version to a new version, follow the link: logmein.com/logmeinbackup.msi
This is the Backup MSI installer package. You can save and run this file which will bring you through the installation process. It will ask you for a valid LogMeIn.com account during the installation process. If you are upgrading it will provide an upgrade option.