I suspect Nero is partially at fault. When I had Nero some time ago, I made the mistake of trying to use its virtual drive function. That immediately disabled Daemon Tools, a far superior virtual drive/emulator. Nero can be bossy like that.
I would go to the Nero site and get the Nero Clean Tools, run them to be certain all traces of Nero are gone. Then run CrapCleaner on the registry (CCleaner will prompt you to back up the registry first. Do so.)
Try re-installing Alcohol, make sure it's working. Then install Nero, and leave its virtual drive severely alone, unless you want to use its virtual drive and eliminate Alcohol. I don't remember, do you have to enable the virtual drive option in Nero when installing, or not? [scratches head]. Anyway, I'd leave it alone, and for goodness sake, don't install Nero's InCD (packet-writing software). If you do, you'll be sorrrrry!
This may sound like I dislike Nero, I don't, it's okay. But folks can easily get themselves in a jam with it when they monkey around with certain things best left alone. It's also unwise to have multiple burning apps on the same computer as Nero, you're almost certain to have conflicts. Many people report that, for them, Nero will not co-exist with Roxio or RecordNow.
Any tools I mentioned can be easily found by googling. Good luck.
