The newer nvidia drivers seem to have disable refresh rate overriding, bad for me. I don't use a crt, but an lcd. I've noticed that with 60hz my eyes hurt pretty bad. I've tried several programs, ended up with rivatuner. Its a pretty nice freeware, very good with forceware drivers. I was able to force my computer to accept 120hz.
*Oops, more of a computer discussion question...forgot it was in off topic.