This is the software publisher’s description.

The Disc image system is an Editor, Converter and a driver that can mount ISO CD/DVD images into a Microsoft Windows 2000/XP/2003 based system. This gives the impression that a new CD/DVD-ROM drive has been added and a disc has been inserted. The small size of the driver and its simple operation allow an integration which is similar to actually using CD/DVD-ROM hardware, but as the drive is virtual, there is no hardware noise or lag. It is even possible to mount as many images as there are available drive letters.

The Disc image system can mount ISO images that contain ISO9660, Joliet, UDF or all three file systems, which on a Windows 2000/XP/2003 based system allows all ISO images to be mounted (if Windows supports the file system then Disc Image will mount it).

For single users the Disc image system allows you to store frequently used CD/DVD images so they can be accessed quickly and quietly (no more loud whirring noises). It will also eliminate the need to have a disc left in the CD/DVD drive when running applications that require access to the disc.

When using on a laptop, it allows better use of the battery as CD/DVD drives require a large amount of power, especially when the drive is running continuously.
ISO Images can be mounted using the Disc image system, allowing them to be tested and verified before being burned to discs with applications such as Nero, thus reducing disc wastage.