Asus K8N nVidia nForce3 Pro 250 GB, Athlon 64 3200+, Hitachi 80 gig SATA 150, Corsair XMS 1 gig PC4000, ATI Radeon Saphire 9600 Pro (256 DDR), Windows XP Pro (64 Bit),Lite-ON SOHD 167T,, Plextor PX-712SA,BenQ 1640.
I am sorry I cannot be of more help, but I think that the .nrg file extension is used only for one or two burning programs. I think one of them might be WinIso, but am not positive. I am pretty sure though that you have an image file burnt in a particular burning program; all you need now is to find the program.
Good luck.
EDIT- I also thought .nrg are associated with Nero, so try the most current Nero.
Asus K8N nVidia nForce3 Pro 250 GB, Athlon 64 3200+, Hitachi 80 gig SATA 150, Corsair XMS 1 gig PC4000, ATI Radeon Saphire 9600 Pro (256 DDR), Windows XP Pro (64 Bit),Lite-ON SOHD 167T,, Plextor PX-712SA,BenQ 1640.
A Try this, instead of double clicking on the NRG file.
1. Open Nero
2. Close the silly New Compilation dialog box
3. If you are using Nero5, File --> Burn Image --> Select the NRG file. If you are using Nero6 then Recorder --> Burn Image --> Select the NRG file
B Something else you can try is to change the burn mode from Track-at-Once to Disc-At-Once or something.
C Last case, open the NRG file up with CDMage (Mode1/2048 if it asks you). File --> Save As and give it a name. CDMage will create a BIN/CUE file for you and you can burn the that the same was a in A but just select the CUE file insead.