Hi Waqqas Riaz
Welcome to Microsoft Vista Answers Forum!
Methods I would recommend are:
Method 1:
Uninstall and reinstall the CD/ DVD drive from the computer
i. Click Start, type devmgmt.msc and press enter.
ii. Expand CD/DVD driver and right click on the sub item and click uninstall.
iii. Restart the computer.
iv. Visit the manufacturer website to download the latest driver.
v. Install the driver and restart the computer for the changes to take effect.
Method 2:
If it was working fine before then you can perform System restore. Restore the computer to earlier time when it was working fine. To restore the computer successfully follow these steps;
i. Click Start, type system restore, right click on System Restore, and click "Run as administrator".
ii. Choose the correct date when the system was working fine and follow the instructions on the wizard to complete the process