As you guys know, if we want Nero, we have to install Nero 8 and later to work on Vista. However, I found out that only the versions from 6.5 to 7.5 aren't compatible at all. Nero 6.3 and earlier (v5, v4...) works because it doesn't have Nero Scout included. It's a really big discovery because I'm a huge fan of the earlier version of Nero. Nero 6.3 is really the best!
Try it out if you have a licence.
P.S : You need to force it (ie. Click "Execute the program anyway" when that compatibility dialog appears)