I have this and I like it. It's a virtual CD program. Basically it makes a copy of your CD and put a "virtual CD" copy of it on your hard drive. So you can store CDs on your HD. It puts a virtual CD icon on your desktop so you can "mount' and "unmount" those virtual CDs.
So, instead of hunting around for my copy of a CD to play a game, all I do is right click on the virtual CD drive and select the appropriate "virtual CD" to mount. And my game thinks I have the physical CD in my drive and it runs.