Apple has not updated BootCamp as of yet to provide updated drivers for Windows 8 as far as I am aware. As such, I wouldn't expect things to work properly. If the Windows 7 drivers don't work, I wouldn't expect the trackpad to function properly at all. You may be able to get the DVD drivers from somewhere else, as it's a standard part, but you don't mention which MacBook Pro you have, so that makes it rather difficult to help.
My main bit of advice would really be to post in the correct area, this is the Mac Pro thread, not the MacBook Pro thread.