By default, Nero will copy it's install and uninstall files in your Local Settings\Temp folder. If you are like me and like a nice clean C-drive, you will keep your temp folders clean and empty.
Well . . . as soon as you empty that temp folder you can no longer uninstall Nero, nor install or uninstall any options. Dumb Nero Installer
Here is the workaround. You'll have to use Nero's cleantools to fix the current install. Then, when you install a new Nero 7 (or update), let the install continue only up to the screen that lets you select NORMAL or CUSTOM install. Click on CANCEL, then FINISH.
Since Nero doesn't clean up its own mess, those setup files will still be in the Temp Folder in its own sub-folder. Go to your Program File folder and create a new folder named Nero. Drag the Nero Setup Folder from your Temp Folder and drop it into the Program Files\Nero folder. (I prefer right-click dragging and using the move command).
Now go to that folder and double-click the SetupX.exe file. Choose the Custom install option and select or unselect components. Then pay attention to where it wants to install the program, and make sure it is going into Program Files\Nero. If not, click Browse and point it there.
After the install, your Nero folder will be registered as the new location of the uninstall files and everything will be all in one place.
Now you can feel free to keep your Temp Folders clean and tidy again

Thanks for the info. I have printed it off in the unlikely event that will be daft enough to desert v6 for v7