You have to use another computer and a USB flash disk to copy the content from the CD to install it on your PC. Or you can buy an external CD/DVD-ROM and install it this way. You can find external DVD-ROMs on NewEgg or Amazon or your local IT store. Make sure choose an external DVD that uses USB as connection.
The software is not available for downloading anymore, and this is the actual way to install it on your PC. There is no need to purchase it anymore.