Your graphics card isn't supported directly in windows 8.1, you have 3 options (2 if using a laptop)
1. downgrade windows to 8 or lower
2. install a newer graphics card
3. attempt the workaround here http://www.minecraftforum.net/forums/support/unmodified-minecraft-client/1868881-windows-8-lack-of-updated-graphics-drivers-solved#c8 (use http://support.amd.com/en-us/download/desktop/legacy?product=legacy2&os=Windows 7 - 64 instead of the ones on the linked page)
The workaround may not work and if you try it be it on your own head.
Alright! Thanks for the help