First at all, I consider important to explain what is a disc image, this is a file which contains information of a CD, DVD or Blu-ray even, having inside the structure of the disk, files and data that is used to execute it without problems.
This image can be saved on a lot of formats (.iso, .ccd, .cue, .nrg and more) and it gives the chance to use it on a PC without the necessity of burning it into a physical disc. As it allows to do so, I use this feature many times to verify if a movie DVD has been built correctly to burn it into a disc later.
For this purpose we will use Daemon Tools Lite to mount the image to be recognized by the PC as if it were inside the CPU physically. This effect will be reached because the tool creates a virtual CD/DVD device where the image will be mounted.
After installing this tools, you will notice the new CD/DVD devices that will appear together with you other devices, then you run Daemon Tools Lite to get it in your task bar beside the clock.
Once the icon shows there, just right-click over it and select the virtual device.
In the virtual device select the "Mount image" option, this will pop up a file selection dialog box, where you have to pick your image disc file, with this the tool will mount the disc.
If the image disk is copy of an autorun disk, the autorun will execute and show the disk, but if it is not, then you could see in the PC devices lists the new disc mounted, this is the manner you could assure your disk works with no problem.
If you are sure your disk is fine then you can unmount it by right-clicking on the tool, selecting you virtual device and clicking on "Unmount image" option.