nvidia g05 or nouveau in TW Live/Install?

My nvidia gt640 video card is temporarily re-installed after the AMD card went kaput. The TW install and Live DVD's both boot but end up with a black screen after the last HDMI symbol appears. The DVD continues reading but the prog is unaware that I can't see anything. I thought that the installers and Live media could work with any card. What are my options to recover the installation and use it with this card UFN?