Well most of the Windows DDK tended to be C, with perhaps some C++ creeping in at the end of my tenure. I'd wager it would just need a recompilation as the driver stuff for USB would mostly be about managing data and whatever the USB Class needed, or funnelling requests from user space. So recompilation to ARM, MIPS, ALPHA, or whatever.
Now my guess would be there's some user space application that facilitates interaction with the driver, or USB, perhaps IOCTL's. Unfortunately CAN is of little functional utility on Windows, so beyond doing firmware updates, or a company doing "CAN Tools" as a business, or people in the modding / tuning scene, I don't suppose Microsoft's going to be facilitating much.
One can't readily make signed .CAT files, but the .INF are mostly about being a chameleon and formulate the script sufficiently to get the driver installed. One could do that directly via the registry and copying files, but that's obviously been complicated by all the AV and exploits over the last decade or two.
