CD or DVD?

How can we detect whether there is CD or DVD in the DVD writer?

thanx in advance

Call API function NeroGetCDInfo and then look at the ncdiMediaType structure member returned.

If you have NERO_SCSI_DEVICE_INFO structure with information of your recorder you can check nsdiMediaSupport field.
If (nsdiMediaSupport & MEDIA_DVD_ANY) > 0 then your recorder is a DVD recorder.

Thatโ€™s correct, but the question was how to determine the type of disk, not the type of device. In this case the device is always a DVD writer, and the variable is whatever media you put inside (CD or DVD).