Looks like the information you are looking for is TargetOSVersion, which is documented in http://msdn2.microsoft.com/en-us/library/ms794553.aspx From: wdmaudiodev-bounce@xxxxxxxxxxxxx [mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx] On Behalf Of Jeff Pages Sent: Tuesday, May 15, 2007 11:56 PM To: wdmaudiodev@xxxxxxxxxxxxx Subject: [wdmaudiodev] Driver selection For a particular device, I have a WaveRT driver for Vista and a WavePCI driver for earlier systems, each with their own inf files. What can I do to stop Vista installing the WavePCI driver, or earlier operating systems from trying to install the WaveRT driver? There's a lot of stuff in the WDK about distinguishing between 9x and NT-based drivers in INF files, but I can't find anything that gets more version-specific. Jeff