Alcohol gets you drunk.
Alcohol 120% is also the name of a program that can burn discs, create disc images (exact copies of a disc that you can put on your HD), and also has a 'virtual drive' which allows you to load disc images so you can use the content of the disc image as if it was a real disc loaded into a DVD/CD drive.
I'm not sure of the specifics of the game or the copyright protection it may use, but if it came on a DVD, it can probably be burned to a DVD, CD to CD. Or you could create a disc image and play it from your hard drive using a virtual drive, as I described above. I can't help with the specifics of the copyright protection, I don't know much about game protections but someone else can probably help, there is another forum on here that may be better able to help (can't recall which forum it is, look around for a forum with game discussion).