Alcohol 120% is one of the most useful and polished commercially-available programs for Windows. It is entirely related to CD/DVD images and can save you a lot of space by allowing you to create “virtual” CD-ROM drives based on CD images. To download it, go to http://trial.alcohol-soft.com/en/download_120.php and try it today.
Once it has been installed, simply mount an image to the virtual drive that it creates by default and enjoy. Notice that you can create additional drives through Options -> Number of Virtual Drives; also, remember that you can assign alternative drive letters to these drives that would strongly differentiate them from physical drives (i.e. X and Y).