With Nero Burning ROM and the Image Recorder you can create disc images from every compilation. The NRG image file format can always be selected whereas the ISO image file format can only be selected from certain compilation types. Nero Burning ROM only enables the possible image file formats.
The NRG image file format was developed by Nero. In contrast to ISO, NRG can be created from every disc and compilation type. This means that even Audio CDs or multisession discs can be saved as an NRG image file.
To create an image file, proceed as follows:   
Click the New button. 
Create a new compilation of your choice.




Using Nero Burning ROM you can create image files for disc types that the installed recorder cannot burn. You can enable this function via the File > Options > Expert Features menu, Enable all supported recorder formats for image recorder check box. The drop-down menu in the Compilation window then makes available all supported disc types.


Select the files that you want to burn.
If you have installed multiple recorders, select Nero Image Recorder from the drop-down menu.
Click the Burn button.
The Burn Compilation window is opened; the Burn tab is in front.
Click the Burn button.
The Save Image File window is opened.
Specify a file name and a storage location for the image file and click the Save button.
The image file is created and saved in the selected storage location. On the screen, a progress bar indicates the progress made while the file is being created. Once the creation process is over, a message window is opened.
Click the OK button.
The message window is closed and you have successfully created the image file.
See also
Expert Features
An image refers to a single file on the hard drive that contains the image of a complete disc. A disc image can be used to create exact copies on media at a later point in time if problems occur during the write process or if no recorder is connected to your PC. The image requires as much free space on the hard drive as the contents of the original disc take up.

Burning With Image Recorder – Creating an Image File