My dear spouse just came back from a business trip and bought me a "nice" present: a shiny Apple (remind me to somehow hide the logo) USB Ethernet Adapter. The people in the store told her it would work just fine with her computer (and mine - A Microsoft Surface Pro, which doesn't come with Ethernet, but which of course has USB). Of course, it didn't.
So, I plugged it in the Surface Pro. As expected, no drivers :-(
Searching the internet did not reveal immediately a (good) solution - I did find some hacked about archive containing drivers for Win98 to WinXP, but nothing suitable. Which got me thinking for 5 minutes. All these iSheep using their Mac with Bootcamp must be able to use this thing. So, I headed over to the Apple support website, where you can download the Bootcamp support software (http://support.apple.com/kb/DL1638). This is one huge archive containing all drivers you would need to get your Mac to work with Win7/8.
So, one task remained: finding out where the driver for my shiny new adapter was to be found. Again, this was made more difficult than necessary: Apple couldn't simply name the directories referring to the device names, but instead had to use the manufacturer of the chipset ... A little poking revealed that the driver I needed for this Apple thingy is found in the Asix folder. After you extract and execute the single .exe in that folder, you have your driver nicely installed. No need to play games with unsigned drivers and the like.
All in all, more difficult than necessary ... hope this helps someone else facing the same hurdles.