If it's DVD it can only run on DVD. The suggestion would be to get a DVD-ROM drive, which is extremely cheap these days. Or you could even get a CD-RW/DVD combo. If that is not an option you could buy the DVD, go to a friend's house with another secondary storage device (an iPod or an external HD), copy the contents of the DVD to the HD, take the HD (and the DVD) back to your house and plug it into your computer, copy the folder to the desktop HD, install it, find a "No-CD" patch and run the game. However, if you have to choose between buying a DVD-ROM and an external HD, I would say go with the DVD, every time.