"What does NBKeyScan.exe actually do? It looks like it is part of Nero 8 BackItUp utility."
BackItUp is the utility bundled as part of the Nero 8 suite designed to setup automated backups of files, folders and important data on your system. NBKeyScan.exe is a specialized part of versions of BackItUp optimized to function with external drives that support a one-step-backup type function. The NBKeyScan.exe utility adds some specific controls for external hard disks to offer a drive power down feature and the ability to launch BackItUp and run a back up operation from the drive by pressing a button on the front of the drive console. While this is possibly a useful feature, it's by no means a required feature of the application and can be safely turned off if you don't need the functionality of making quick backups by pressing a button on the drive.