Inspiron 17R 5720 optical drive not working

I don't know when the last time was that it worked, but one day I went to use it and nothing

The device manager sees it and says it has the correct and most up to date drivers but device manager show that little yellow triangle sign with the exclamation point.

• HL-DT-ST DVD+-RW GT80N ATA Device
  • Device Status: "Windows cannot load the device driver for this hardware. The driver may be corrupted or missing. (Code 39)"

OS: Windows 7 Ultimate

I purchased an external USB DVD drive yesterday, but that shows the same error. No drivers are needed for it. I tried in on another PC and the external drive was found and worked so there is something wrong with whatever it is that runs CD/DVD hardware.

I downloaded and installed every driver on dells support page for my lappy .... no joy and the diagnostic test resulted in no problems detected,

I hope someone can help otherwise this laptop has a date with a 9mm.

Thanks for your time.