Our device relies on a built-in windows driver (usbser.sys). Do we still need to go through WHQL testing or can we install in such a way that the user won't see a warning about not passing Logo testing? I found http://support.microsoft.com/kb/837637 but it's not clear to me if this will do what I want. Does it matter whether I use DPInst program or have my own program that calls DriverPackagePreinstall?
[Edit: changed "Our code" to "Our device" based on comment]
Still not a 100% sure but some general pointers: