I’m trying to copy a DVD with CloneDVD now, and i get this message:
Unable to read files from
F:/VIDEO_TS
F:/VIDEO_TS/VTS_03_0.IFO: Unable to open file
What the hell?! The DVD is burned already, so it’s weird it’s a problem.
What should i do? Any suggestions? I’ve had the same error with DVD Shrink.
I was planning to watch this DVD soon, so fast help would be appreciated 
If you can’t read a file from a burned disc, probably you have a coaster.
Try to read the disc in another drive; some are able to read ruined discs better.
Check also if the disc is dirty or scratched. Cleaning can solve your problem.
As geno says it’s most likely that the burned disk was badly burned & is unreadable in parts.
And be a little patient, don’t bump the thread so quickly as responses are not always instantaneous.
you can find many dvd tools at http://www.yaodownload.com/video-design/ such as some dvd ripper, dvd converter, dvd copy tools 
as has been said, if you can’t read the file from the burned disc then you have a poor quality burn.
get out the original and use your original copy if you’re going to watch that tonight then make a new backup when you’re done…