Another issue I have had with Windows 8 in Bootcamp on a Mac is that the trackpad drivers did not initially install correctly and I wasn’t able to use it at all. I was able to solve that by following these steps.
Go to Device Manager and on the two “Touchpad” entries with the bang on them, go to “Update Driver” -> “Browse My Computer” -> “Let me pick from a list…” and change them both to USB Input Device. Reboot.
Go back to Device Manager, do an “Update Driver” again, let it search automatically, and one comes back as Apple Multitouch and the other as Apple Multitouch Mouse. Reboot again, trackpad will be working and will show up in Boot Camp control panel.