Since Carbonite runs after Windows and drivers load your files can be backed up. However that's not "backup" in the strictest sense since to reach a true state of backup we never have less than 2 copies at any time. Let's say you only use Carbonite and you lose your PC. Your files are now hostage and subject to any issue/problem without any other backups.
RAID 1 was great for gamers but I wonder at times.