To try to identify why your laptop is not recognizing an external CD/DVD drive, here are some steps you can try:

1. Make sure the drive is properly connected to the laptop.
2. Check the drive in the device manger to see if it is recognized.
3. Try a different USB port.
4. Check to see if the CD/DVD drive is listed in BIOS.
5. See if drivers need to be updated.
6. If the drive is external, ensure you have the power adapter and that it is connected.