Hello fudge, seems to me you haven't got the right Nero app installed on your PC - never mind, a free and better program is Imgburn, which will write.nrg files.
http://www.imgburn.com/
ImgBurn supports a wide range of image file formats - including BIN, CUE, DI, DVD, GI, IMG, ISO, MDS, NRG and PDI.
Here is what you do:
First, double-click to open Davren's rar file you downloaded, and then drag the Fiat Stilo.nrg file on to your desktop.
Download ImgBurn,(it's free efficient and lightweight) only 2.1MB
http://download.softpedia.com/dl/95...oftware/cd_dvd_tools/SetupImgBurn_2.5.0.0.exe
When it's downloaded, either double-click to install, (or probably right-click and "run as administrator" if using Vista).
Click "Finish" at end of install and ImgBurn will start.
You will be presented with 6 graphical options - choose top left, "Write Image File to Disc". Click on it.
New window opens, at top left see, "Please select a file" then along the line click the small image of a folder to browse to the location of the Fiat Stilo.nrg file i.e. Desktop.... see it? Click it! Scroll down till you see the Fiat Stilo.nrg file, and double-click on it.
Now you should see the file selected as "Source" top left of ImgBurn window,
Nearly there - put a new CD in the drive. At bottom right click on speed dropdown menu and choose 1x or 2x.
Move to left and click the "write icon".
The disc will now be written.
I tried to do this in a simple step-by-step way. Hope it helps.