Did you reinstall the drivers?
First of all, its important that you understand that you CAN'T reinstall the drivers, alone.
There IS NO stand alone driver. The driver is installed when the OS is installed, from the OS disk ONLY.
SECOND: it's caused by corruption of the registry. The corruption occurs when the OS is updated. This has been reported thousands of times.
THIRD: READ THIShttp://answers.microsoft.com/en-us/windows/forum/windows_vista-hardware/dvd-driver-corrupt-in-the-registry/874e7a9e-3825-43d1-9b06-2bacc1184f37
NEVER: install "free" software that promises it will "fix problems." It's a SCAM! YOU have been warned. Use ONLY Microsoft disk to repair the operating system.