Problems with Vostro 1015 DVC/CD-ROM Drive

I have a Vostro 1015 running Windows 7. My DVD/CD-ROM drive (Optiarc DVD +-RW AD-7585H ATA) stopped working a couple of weeks ago. 

When I go to the Device Manager I see that there is an exclamation mark by the DVD/CD-ROM drive. When I click on 'properties' it says the following under device status: "Windows cannot load the device driver for this hardware. The driver may be corrupted or missing. (Code 39)"

I think I have located the driver and downloaded it. It gives me a 'WIN' folder and a 'DOS' folder. When I click on the 'WIN' folder and click on driver application, a dialogue box pops up saying: "You do not have administrator rights to process or no device is recognised" (image attached).

I'm not great with computers so any tips on what I can try would be much appreciated.

Thanks,

Will