"it says the disc is broken," Broken is an issue that could be any part of your computer. A disk may be 100% good and fail because of optical reader, memory, cpu, motherboard or what not.
I'd be inclined to say it was the disk but test the disk on another system. It still may be that some bits are slightly off. Borrow a usb dvd reader and try it again. Run memtest for a few days.