We link to the 'trial' downloads as these are always up to date, these are the normal full versions and are unlocked when you put your license key in.
Windows 32-bit Backup Agent http://repo.r1soft.com/trials/ServerBackup-Windows-Agent-x86.msi
Windows 64-bit Backup Agent http://repo.r1soft.com/trials/ServerBackup-Windows-Agent-x64.msi