I've got no idea, but under no circumstances can it be an .inf file! Don't you think so? Yes it is possible. Info on this type of file is pretty slim, so I am guessing real info on creating them are on websites behind password, such as Partner level access for Microsoft sites. I found one post on MSDN Social where someone was creating a Vista sidebar gadget and this sort of code was present in his post. Unfortunately, I'm not about to log into MS Partner to search around for you, since everything in there is NDA anyways. Thanks a lot. BTW, I noticed that once Windows 7 is installed, the file in \Windows\System32\DriverStore\FileRepository\wdmaudio.inf_x86_neutral_aed2a4456700dfde is just the same as the one in \Windows\inf. It's really interesting:)