Problem: I tried to get an old CD-burning program installed in Windows XP Mode on a 64-bit Windows 7 workstation and my CD/DVD drives stopped working on the machine. I soon determined out that this happened because the CD-burning program installed an old and incompatible driver (W2K3x64, unsigned) which disabled the Windows 7 driver. The way I determined this was by opening Device Manager, opening the properties of the CD/DVD drive, selecting the Drivers tab, and clicking Driver Details. This showed that there were two drivers for the device: cdrom.sys (Microsoft’s in-box driver) and an additional third-party driver from the vendor of the old CD-burning program. Installing the vendor’s program under Windows XP Mode had disabled the cdrom.sys driver and enabled the vendor’s driver, but unfortunately the vendor’s driver was an unsigned driver designed for Windows Server 2003 x64 that didn’t work under Windows 7 x64. What to do?
Resolution: To get my CD/DVD drives working again, I had to delete the UpperFilters registry key found under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E965-E325-11CE-BFC1-08002BE10318}. Installing the CD-burning program under Windows XP Mode had created this registry key in Windows 7. For more details concerning this issue and how to resolve it, see Microsoft Knowledge Base article
http://support.microsoft.com/kb/929461.
Moral of the Story: Don’t be cheap—if you upgrade to a new OS, make sure you get upgraded versions of your apps as well!
Mitch Tulloch is a seven-time recipient of the Microsoft Most Valuable Professional (MVP) award and widely recognized expert on Windows administration, deployment and virtualization. For more tips by Mitch you can follow him on Twitter or friend him on Facebook.
