Sorry for undigging...
I have exactly the same problem, the DVD-rom was working well and then it stopped reading CD/DVD... I tried everything... Change the driver, uninstall all additional drivers, uninstall reinstall driver, registry edit of the device itself, disabled/enable autorun, disable/enabled burning feature of Windows, Googled a lot, Scanned the computer agains Malware, Against Virus with different software and of course wasted number of hours on this problem... The worst is the fact that if I plug a USB CD/DVD Rom it's the same, impossible to read a disc ! I also tried with a virtual CD/DVD rom drive... Again the same... I created a virtual linux Machine Within Virtual box and the CD/DVD Rom reads drive normally... For the moment I run a Virtual Machine with linux with a Samba Share on the CD/DVD Rom so I can use my CD/DVD Rom by making a network drive... This is crazy and this is very frustrating... I'm an It Professionnal since 20 years and it's the first time I encounter such problem that I'm unable to resolve... Recently another computer running windows 7 was "infected" by the same problem... I could reinstall Windows but I really don't like when I can't find a solution to a problem ! Thanks in advance