It is exactly as HWKE states. You need to burn the 'backup files' to a disc.
This short tutorial on using DVD Shrink may help.
Alternatively, if you want to watch these movies on PC only and don't want to use up discs, you can extract the data as an image, e.g.
cue/bin
iso
ccd (CloneCD)
bwt (Blindwrite)
mds (Media Descriptor File)
cdi (Discjuggler)
nrg (Nero)
pdi (Instant CD/DVD)
b5t (BlindWrite 5)
You can play these images on your PC using Daemon Tools as though they had been burned to a disc.
You can download Daemon Tools
here and view the user guide
here