I think ( and I could be wrong here) but if you go to START > RUN > and type in DXDIAG it will open a window thats gives you virtually ALL the info on what is inside your PC. You should be able to find out what graphics and sound cards you have, what model and who they are made by. Then you can go to the manufacturers websites, and most manufacturers have drivers you can freely download

And to top it all off, it's legal