Windows 8 OSD (On screen display)
If you have installed Windows 8 in a bootcamp partition, you may notice that everithing seems to work pretty fine. However, if you are missing the OSD feedback for volumen changes this programm will do the job:
http://matthew.malensek.net/#/Software/
If you know similar apps that gives a similar OSD for brightness i will be happy to hear about.
Windows 7, Bootcamp bluetooth drivers