I have it. Have not installed it, but don't know what to do with it. TFAH.

Really!!! So do I ! Last time I looked I had 3 of them! Just a guess but would say they are used as a Virtual Drive! For games, ISO images.

Image files are snapshots of a CD or DVD disc. Virtual CD/DVD drives are created in software to emulate a real drive. You mount the image file with the virtual drive software, which is emulates inserting the original disc in your CD/DVD drive. You'll see it appear in Explorer under My Computer. Useful for keeping often used discs on your PC instead of digging them out and handling them. They have other uses but I can't go into that here.

Don't the contents of that virtual drive go away if the machine is shut down?

To be on the safe side I'd unmount the image before logging off and shutdown.

Like TigerZai said, the main benefit of a virtual cd drive is to use apps like games, dictionaries, learning, even movies, not from disc - CD or DVD - but from hdd. This lets you limit damages to the respective media, and enhances app performance, since the data is already on yr hdd. Personally, I prefer to use Virtual CD-drive from MS Downloads; it's tiny and standalone, nu install necessary, and works like a dream.