I have a core i5 2500k a ssd and a radeon hd 6700 or something like that, I run new vegas at max setting on 2560 x1440. however when i press play in steam i get the launch screen which tells me it has selected ultra high settings and then when i press play nothing happens, any help guys?

Have you tried to start the game launcher manually with admin rights?
Do you have all Runtimes, that are needed for the game?
Is DirectX and your graphic card driver up-2-date?

Check this stuff out...if the error still is there, than write again