Does your computer start? Or is it stuck at the BIOS screen. I posted this up before. The GTX 460 is having some major issue. I got lucky since replace mine and nothing happen since.
Here is the link
http://forums.nvidia.com/index.php?showforum=199
There are a few threads about it. If it is a brand new card you might want to bring it back to the store and get a new one.