Custom Assembly not reading

[santojmezzaroba]

I have a portable PC (not a laptop) with Microstudio installed. The Drive is a
PX-712A. When working in the Custom Assembly tab I click Add tracks from CD.
A box appears saying "Select a reading drive (CDROM)". I'm lost at this point.
At the bottom of the screen next to Reading Drive "Plextor DVDR PX-712A 1.05
is listed. Discs will play on the play tab and I can duplicate on the import tracks tab. The same message appears when I try to use the "Duplicate disc" tab.
Help is appreciated.