It's a bit difficult performing remote hardware support with no idea of the Operating System, laptop make, etc...
But, basically I would hazard one of three causes:
1. It's a Windows Laptop and an automatic MS update has been applied that has disabled the drive
2. You've managed to get a nasty trojan/virus
3. Your DVD/CD drive is broken.
You might want to try booting your laptop in "Safe" mode. If, when you do this, the DVD/CD is accessible, you can rule out (3), but 1 & 2 remain a possibility. However, if it doesn't work, your DVD drive may have failed - the stepper motor or laser may have broken, it happens - in this case, time to replace the drive.
If the drive does work after booting in Safe Mode, run a Virus scan to check for anything nasty...
After this check whether MS has installed any automatic updates since the drive last worked and see if you can roll them back.
From what you say (3) sounds the most likely...