Hey, do you happen to have dual graphics with nvida and intel?
Because i just found out that if you have a laptop like i do (nvidia g310m) and discrete intel graphics and you go to your desktop in Windows 8 -> right click -> go to nvidia configuration and you set "Always use Nvidia Graphics" it does work.
I guess this is because Windows 8 does not only install a general Nvidia driver when you install W8 but also a general Intel video driver. So i guess that you can also intall the correct driver for your intel graphics and it should work, but with mods like tekkit i would recommend to use the Nvidia anyway.
Sorry for my english, it is not my native language.