Howdy:
I am dumping every last CD & DVD to a spare HD. I know some nice free/open source Windows software to do that.
What I don't have is experience with free/open source software that can READ or mount those .iso files from the HD, so when my daughter savages the physical Monsters Inc DVD I can play the .iso from the external HD.
(Note: this also gives me a little more parental control, as the kiddos know how to operate the DVD/TV systems, but can not yet hack into my Windows login.)