The proper hoops for this probably involve contacting nero and explaining the situation and waiting for the answer from them.
a faster, and likely illegal, solution would be to use a crack or serial search to find a workaround (http://serials.ws/ isn't horrible, as long as you are very specific with your search and don't download anything...just wait until you can SEE the key on the screen...it is safe to cut and paste). this is somewhat dangerous...as those types of sites often have pornographic images / advertisements and are habitually plagued with malicious software and scripts. that said, i've found times when they provided the most efficient route to getting my legitimate software working properly.
anyway, if you have any specific version (open nero and go to help / about / product information or something) number and build number, using that information would be vital search information to ensure you get the right number. if you can't get that far into the program, the information may be available in the documentation on the CD. best of luck!

Chien klab chmata roho tkhawdou

If the nero is installed on your pc so you can find it with softkey revealer
http://cakirbey.googlepages.com/softkeyrevealer