If you mean software rather than movies, the installed versions are unlikely to re-install if you copy them to DVD. You're better off backing them up, using a program that allows backups to span media. Given the cost of hard drives, you might consider simply backing up to a hard drive, or taking a disk image using something like Acronis (not free) or Easeus (free).
If you do make a backup, make sure you know how to restore it, too...