Well, my DVD rewritable drive, and its companion the CD rewritable drive have decided they don't like my Guild Wars Nightfall CD. (not surprised about the CD-R/RW cause GW is a DVD disc.) I have been re-installing GW with both of its expansions, factions and nightfall. Factions worked fine but nightfall has yet to be recognised by the DVD drive. It works with the other computers with the house. Whats wrong?! (ps. this is my dads pc so i have no idea about the OS CPU/Ram or Make/Model except that its a Dell one)

Optic drives develop problems. They get dirt on their lenses and eventually the lasers wear out. It is also possible the lenses become misaligned due to bumping. If running a lens-cleaning disk does not improve the reading performance then it might be time to replace the drive. By the way, are the disks you are trying to instal factory originals or burned copies? I ask this because I recently had to replace a dvd drive that would only read commercially produced disks. The laser was too weak to handle burned copies. I used to have a signature but it disappeared and I just couldn't be bothered writing another so please feel free to ingore this.

Can you make another copy of that disc? I have a dvd-rom I created on this PC (nothing copyrighted, just shedloads of my old files I wanted to clear off my hard drive but didn't want to lose for good). I later found that the original disk wouldn't read in either drive in this PC, yet a copy of the unreadable disc made on another machine works fine...