Did you use DriverPack Sound? I guess not. Well why is this Realtek drivers installed? Very easy: each device has a unique DeviceID (well, it should be unique...), and as you know Realtek is a manufacturer that sells its chips to many other brands. This brand 'crystal' as you say, has simply used a chip of Realtek and kept the same DeviceID. That's why Realtek's drivers are getting installed. There are a couple of solutions: 1. download Realtek's newest driver, let Windows install this one (OemPnPDriversPath in your winnt.sif) and hope your soundcard will work properly. 2. install Crystal's driver by its setup 3. install Crystal's driver with the devcon utility. 4. remove the realtek driver out of drivers.cab and add Crystal's one (again with OemPnPDriversPath in your winnt.sif) I've ranked them by difficulty: the first one is the easiest.