I've just performed a fresh install of Windows 7 x64 on my Toshiba Satellite Laptop but it seems that I'm unable to run some DX10 apps using the Nvidia 740M GPU, but they run with the integrated Intel GPU.
I've tried both with Passmarks's PerformanceTest (run a DX10 benchmark) and with Civilization 5 (DX10 game that once ran fine on this laptop), and both hang with the Nvidia GPU, but they run with the Intel GPU.
This was with all latest drivers and OS updates. I've reinstalled two different older Nvidia drivers (353.30 and 359.06) and also reinstalled DirectX (KB2670838), the apps will still hang if ran using the Nvidia GPU.
Not sure if it's helpful but I had to install the DirectX End-User Runtimes (June 2010) because of Civ5.
