It is still possible to do this backup with free tools. First you'll need DVDFab HD Decrypter. It is the free ripping/decryption section of DVDFab and will continue to function even after the trial for the main section of DVDFab expires. Found here: http://www.dvdfab.com/free.htm
Next up, you might need DVDShrink. Most commercial dvds are too large to fit onto a regular single layer dvd, so you either cut out extras, and see if that makes it small enough, or you compress the video to fit. (many people do both when necessary) You can find DVDShrink here: http://www.cdfreaks.com/software/Copy-DVD-Movie-Software/DVDshrink/DVDShrink.html
You can burn the resulting dvd with Roxio, but I like a free burning program called ImgBurn. You can download it here: www.imgburn.com
While you have the free 30 day trial period for DVDFab, you might want to explore its capabilities and see if it is worth the price of buying the program. It is an all-in-one dvd backup program.
You might also want to look through some guides for these programs: Official guide for DVDFAb
DVDShrink guides at www.mrbass.org or www.dvdshrink.info
ImgBurn guides: http://forum.imgburn.com/index.php?showforum=4