An NRG file is a DVD image file created by the DVD-burning program Nero, while an MP4 file is a video file that can be used in portable media devices, such as the iPod. An NRG file can be changed into MP4 files by converting it into a more universal DVD image file and then converting that image into MP4 files. Note that this task cannot be completed using native software; two separate converters must be used to convert these files.
Download an NRG to ISO converter at weethet.nl (See Resources) and install the converter onto your computer.
Open the conversion program. Click on "File" and then "Open" to locate your NRG file. Double-click on the NRG file and then click on "Convert." Your NRG file will be converted to an ISO file.
Download an ISO ripping program at free-news-release (See References) and dvdsisoripper.com (see Resources). Install the program.
Open the program. Click on the DVD icon and then "Open ISO Files." Select your newly converted ISO file from the Explorer window.
Click on the "Profile" drop-down menu and select MP4 as your output format. If you wish to use the MP4 for a specific device, you will be able to choose what type of MP4 you will end up with.
Choose which language subtitle you would like and edit your video length using the tools of the program. You can also merge several video chapters together if you wish by clicking the "Merge" button.
Click "Convert" to convert your ISO file into separate or one large MP4 file.