don't know which version you are using but OEM versions of Nero 7 don't seem to support the lightscribe function
if the function is grayed out I found following on the Nero site:
- Why is the LightScribe option in Nero 7 grayed out and not activated?
Please check both of the following settings:
- In Windows, go to Start > Settings > Control Panel > Administrative Tools > Services > LightScribeService Direct Disc Labeling Service. Right-click LightScribeService Direct Disc Labeling Service.
- In Windows, go to > Start > Settings > Control Panel > Administrative Tools > Local Security Policy > Local Policies > Security Options. Double-click the entry Devices: Restrict CD-ROM access to locally logged-on user only.